std: Stabilize APIs for the 1.6 release

This commit is the standard API stabilization commit for the 1.6 release cycle.
The list of issues and APIs below have all been through their cycle-long FCP and
the libs team decisions are listed below

Stabilized APIs

* `Read::read_exact`
* `ErrorKind::UnexpectedEof` (renamed from `UnexpectedEOF`)
* libcore -- this was a bit of a nuanced stabilization, the crate itself is now
  marked as `#[stable]` and the methods appearing via traits for primitives like
  `char` and `str` are now also marked as stable. Note that the extension traits
  themeselves are marked as unstable as they're imported via the prelude. The
  `try!` macro was also moved from the standard library into libcore to have the
  same interface. Otherwise the functions all have copied stability from the
  standard library now.
* The `#![no_std]` attribute
* `fs::DirBuilder`
* `fs::DirBuilder::new`
* `fs::DirBuilder::recursive`
* `fs::DirBuilder::create`
* `os::unix::fs::DirBuilderExt`
* `os::unix::fs::DirBuilderExt::mode`
* `vec::Drain`
* `vec::Vec::drain`
* `string::Drain`
* `string::String::drain`
* `vec_deque::Drain`
* `vec_deque::VecDeque::drain`
* `collections::hash_map::Drain`
* `collections::hash_map::HashMap::drain`
* `collections::hash_set::Drain`
* `collections::hash_set::HashSet::drain`
* `collections::binary_heap::Drain`
* `collections::binary_heap::BinaryHeap::drain`
* `Vec::extend_from_slice` (renamed from `push_all`)
* `Mutex::get_mut`
* `Mutex::into_inner`
* `RwLock::get_mut`
* `RwLock::into_inner`
* `Iterator::min_by_key` (renamed from `min_by`)
* `Iterator::max_by_key` (renamed from `max_by`)

Deprecated APIs

* `ErrorKind::UnexpectedEOF` (renamed to `UnexpectedEof`)
* `OsString::from_bytes`
* `OsStr::to_cstring`
* `OsStr::to_bytes`
* `fs::walk_dir` and `fs::WalkDir`
* `path::Components::peek`
* `slice::bytes::MutableByteVector`
* `slice::bytes::copy_memory`
* `Vec::push_all` (renamed to `extend_from_slice`)
* `Duration::span`
* `IpAddr`
* `SocketAddr::ip`
* `Read::tee`
* `io::Tee`
* `Write::broadcast`
* `io::Broadcast`
* `Iterator::min_by` (renamed to `min_by_key`)
* `Iterator::max_by` (renamed to `max_by_key`)
* `net::lookup_addr`

New APIs (still unstable)

* `<[T]>::sort_by_key` (added to mirror `min_by_key`)

Closes #27585
Closes #27704
Closes #27707
Closes #27710
Closes #27711
Closes #27727
Closes #27740
Closes #27744
Closes #27799
Closes #27801
cc #27801 (doesn't close as `Chars` is still unstable)
Closes #28968

src/test/auxiliary/allocator-dummy.rs

@@ -10,7 +10,7 @@
 
 // no-prefer-dynamic
 
-#![feature(allocator, no_std, core, core_intrinsics, libc)]
+#![feature(allocator, core_intrinsics, libc)]
 #![allocator]
 #![crate_type = "rlib"]
 #![no_std]

src/test/auxiliary/allocator1.rs

@@ -10,7 +10,7 @@
 
 // no-prefer-dynamic
 
-#![feature(allocator, no_std, core)]
+#![feature(allocator)]
 #![allocator]
 #![crate_type = "rlib"]
 #![no_std]

src/test/auxiliary/allocator2.rs

@@ -10,7 +10,7 @@
 
 // no-prefer-dynamic
 
-#![feature(allocator, no_std, core)]
+#![feature(allocator)]
 #![allocator]
 #![crate_type = "rlib"]
 #![no_std]

src/test/auxiliary/allocator3.rs

@@ -10,7 +10,7 @@
 
 // no-prefer-dynamic
 
-#![feature(no_std, allocator)]
+#![feature(allocator)]
 #![no_std]
 #![allocator]
 #![crate_type = "rlib"]

src/test/auxiliary/lang-item-public.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std, core, libc)]
+#![feature(libc)]
 #![no_std]
 #![feature(lang_items)]
 

src/test/auxiliary/needs_allocator.rs

@@ -10,7 +10,7 @@
 
 // no-prefer-dynamic
 
-#![feature(no_std, needs_allocator)]
+#![feature(needs_allocator)]
 #![no_std]
 #![needs_allocator]
 #![crate_type = "rlib"]

src/test/auxiliary/no_std_crate.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std)]
 #![no_std]
 
 pub fn foo() {}

src/test/auxiliary/weak-lang-items.rs

@@ -13,7 +13,6 @@
 // This aux-file will require the eh_personality function to be codegen'd, but
 // it hasn't been defined just yet. Make sure we don't explode.
 
-#![feature(no_std)]
 #![no_std]
 #![crate_type = "rlib"]
 

src/test/compile-fail/cfg-attr-crate-2.rs

@@ -12,6 +12,6 @@
 
 // https://github.com/rust-lang/rust/issues/21833#issuecomment-72353044
 
-#![cfg_attr(broken, no_std)] //~ ERROR no_std is experimental
+#![cfg_attr(broken, no_core)] //~ ERROR no_core is experimental
 
 fn main() { }

src/test/compile-fail/derive-no-std-not-supported.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std)]
 #![no_std]
 
 extern crate core;

src/test/compile-fail/fail-no-dead-code-core.rs

@@ -10,10 +10,9 @@
 
 #![deny(dead_code)]
 #![allow(unreachable_code)]
-#![feature(core)]
-
-#[macro_use] extern crate core;
 
+#[macro_use]
+extern crate core;
 
 fn foo() { //~ ERROR function is never used
 

src/test/compile-fail/gated-no-core.rs

@@ -8,6 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![no_std] //~ ERROR no_std is experimental
+#![no_core] //~ ERROR no_core is experimental
 
 fn main() {}

src/test/compile-fail/lint-dead-code-1.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std)]
 #![no_std]
 #![allow(unused_variables)]
 #![allow(non_camel_case_types)]

src/test/compile-fail/no-std-inject.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std, core)]
 #![no_std]
 
 extern crate core; //~ ERROR: an external crate named `core` has already

src/test/compile-fail/no_owned_box_lang_item.rs

@@ -12,8 +12,8 @@
 
 // error-pattern: requires `owned_box` lang_item
 
+#![feature(lang_items, box_syntax)]
 #![no_std]
-#![feature(lang_items, no_std, box_syntax)]
 
 fn main() {
     let x = box 1i32;

src/test/compile-fail/placement-expr-unstable.rs

@@ -11,7 +11,6 @@
 // Check that placement in respects unstable code checks.
 
 #![feature(placement_in_syntax)]
-#![feature(core)]
 
 extern crate core;
 

src/test/compile-fail/single-primitive-inherent-impl.rs

@@ -12,7 +12,6 @@
 
 #![crate_type = "lib"]
 #![feature(lang_items)]
-#![feature(no_std)]
 #![no_std]
 
 // OK

src/test/compile-fail/unused-attr.rs

@@ -10,7 +10,7 @@
 
 #![deny(unused_attributes)]
 #![allow(dead_code, unused_imports)]
-#![feature(core, custom_attribute)]
+#![feature(custom_attribute)]
 
 #![foo] //~ ERROR unused attribute
 

src/test/compile-fail/warn-pub-extern-crate.rs

@@ -8,11 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// Check that `pub extern crate` gives a warning.
-
+#![feature(rustc_attrs)]
 
 pub extern crate core; //~WARN `pub extern crate` does not work
-//~^ ERROR core
 
-fn main() {
-}
+#[rustc_error]
+fn main() {} //~ ERROR: compilation successful

src/test/compile-fail/weak-lang-item.rs

@@ -12,7 +12,6 @@
 // error-pattern: language item required, but not found: `panic_fmt`
 // error-pattern: language item required, but not found: `eh_personality`
 
-#![feature(no_std)]
 #![no_std]
 
 extern crate core;

src/test/run-make/alloc-extern-crates/fakealloc.rs

@@ -9,10 +9,8 @@
 // except according to those terms.
 
 #![crate_type = "rlib"]
-#![feature(no_std)]
 #![no_std]
 
-
 #[inline]
 pub unsafe fn allocate(_size: usize, _align: usize) -> *mut u8 { 0 as *mut u8 }
 

src/test/run-make/no-duplicate-libs/bar.rs

@@ -8,9 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(lang_items, no_std, libc)]
-#![no_std]
+#![feature(lang_items, libc)]
 #![crate_type = "dylib"]
+#![no_std]
 
 extern crate libc;
 

src/test/run-make/no-duplicate-libs/foo.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(lang_items, no_std, libc)]
+#![feature(lang_items, libc)]
 #![no_std]
 #![crate_type = "dylib"]
 

src/test/run-make/use-extern-for-plugins/foo.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std)]
 #![no_std]
 #![crate_type = "lib"]
 #![crate_name = "a"]

src/test/run-pass/cfg-attr-crate.rs

@@ -12,6 +12,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![cfg_attr(not_used, no_std)]
+#![cfg_attr(not_used, no_core)]
 
 fn main() { }

src/test/run-pass/derive-no-std.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std, rand, collections, rustc_private)]
+#![feature(rand, collections, rustc_private)]
 #![no_std]
 
 extern crate rand;

src/test/run-pass/for-loop-no-std.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(lang_items, start, no_std, core_slice_ext, collections)]
+#![feature(lang_items, start, collections)]
 #![no_std]
 
 extern crate std as other;

src/test/run-pass/format-no-std.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(lang_items, start, no_std, collections)]
+#![feature(lang_items, start, collections)]
 #![no_std]
 
 extern crate std as other;

src/test/run-pass/issue-13655.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(unboxed_closures, core)]
+#![feature(fn_traits, unboxed_closures)]
 use std::ops::Fn;
 
 struct Foo<T>(T);

src/test/run-pass/issue-14958.rs

@@ -10,7 +10,7 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(unboxed_closures, core)]
+#![feature(fn_traits, unboxed_closures)]
 
 trait Foo { fn dummy(&self) { }}
 

src/test/run-pass/issue-14959.rs

@@ -10,7 +10,7 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(unboxed_closures, core)]
+#![feature(fn_traits, unboxed_closures)]
 
 use std::ops::Fn;
 

src/test/run-pass/issue-16739.rs

@@ -11,7 +11,7 @@
 
 #![allow(unknown_features)]
 #![feature(box_syntax)]
-#![feature(unboxed_closures, core)]
+#![feature(unboxed_closures, fn_traits)]
 
 // Test that unboxing shim for calling rust-call ABI methods through a
 // trait box works and does not cause an ICE.

src/test/run-pass/issue-18661.rs

@@ -13,10 +13,8 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(unboxed_closures, core)]
-
 pub fn inside<F: Fn()>(c: F) {
-    c.call(());
+    c();
 }
 
 // Use different number of type parameters and closure type to trigger

src/test/run-pass/issue-19098.rs

@@ -8,18 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// pretty-expanded FIXME #23616
-
-#![feature(unboxed_closures, core)]
-
 pub trait Handler {
     fn handle(&self, &mut String);
 }
 
-impl<F> Handler for F
-where F: for<'a, 'b> Fn(&'a mut String) {
+impl<F> Handler for F where F: for<'a, 'b> Fn(&'a mut String) {
     fn handle(&self, st: &mut String) {
-        self.call((st,))
+        self(st)
     }
 }
 

src/test/run-pass/issue-19982.rs

@@ -10,7 +10,7 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(core,unboxed_closures)]
+#![feature(fn_traits, unboxed_closures)]
 
 #[allow(dead_code)]
 struct Foo;

src/test/run-pass/issue-20544.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![feature(unboxed_closures)]
-#![feature(core)]
+#![feature(fn_traits)]
 
 struct Fun<F>(F);
 

src/test/run-pass/last-use-in-cap-clause.rs

@@ -10,21 +10,15 @@
 
 // Make sure #1399 stays fixed
 
-
-#![allow(unknown_features)]
-#![feature(box_syntax)]
-#![feature(unboxed_closures, core)]
-
 struct A { a: Box<isize> }
 
 fn foo() -> Box<FnMut() -> isize + 'static> {
-    let k: Box<_> = box 22;
+    let k: Box<_> = Box::new(22);
     let _u = A {a: k.clone()};
     let result  = || 22;
-    // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
     Box::new(result)
 }
 
 pub fn main() {
-    assert_eq!(foo().call_mut(()), 22);
+    assert_eq!(foo()(), 22);
 }

src/test/run-pass/no-std-1.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std)]
 #![no_std]
 
 extern crate std;

src/test/run-pass/no-std-2.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std)]
 #![no_std]
 
 extern crate std;

src/test/run-pass/no-std-3.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std)]
 #![no_std]
 
 extern crate std;

src/test/run-pass/overloaded-calls-param-vtables.rs

@@ -12,7 +12,7 @@
 
 // pretty-expanded FIXME #23616
 
-#![feature(unboxed_closures, core)]
+#![feature(unboxed_closures, fn_traits)]
 
 use std::marker::PhantomData;
 use std::ops::Fn;

src/test/run-pass/overloaded-calls-simple.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 
-#![feature(lang_items, unboxed_closures, core)]
+#![feature(lang_items, unboxed_closures, fn_traits)]
 
 use std::ops::{Fn, FnMut, FnOnce};
 

src/test/run-pass/overloaded-calls-zero-args.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 
-#![feature(unboxed_closures, core)]
+#![feature(unboxed_closures, fn_traits)]
 
 use std::ops::FnMut;
 

src/test/run-pass/regions-copy-closure.rs

@@ -8,10 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
-#![feature(unboxed_closures, core)]
-
 struct closure_box<'a> {
     cl: Box<FnMut() + 'a>,
 }
@@ -25,9 +21,8 @@ pub fn main() {
     assert_eq!(i, 3);
     {
         let cl = || i += 1;
-        // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
         let mut cl_box = box_it(Box::new(cl));
-        cl_box.cl.call_mut(());
+        (cl_box.cl)();
     }
     assert_eq!(i, 4);
 }

src/test/run-pass/regions-static-closure.rs

@@ -8,10 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
-#![feature(box_syntax)]
-#![feature(unboxed_closures, core)]
-
 struct closure_box<'a> {
     cl: Box<FnMut() + 'a>,
 }
@@ -21,11 +17,10 @@ fn box_it<'a>(x: Box<FnMut() + 'a>) -> closure_box<'a> {
 }
 
 fn call_static_closure(mut cl: closure_box<'static>) {
-    cl.cl.call_mut(())
+    (cl.cl)();
 }
 
 pub fn main() {
-    // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
     let cl_box = box_it(Box::new(|| println!("Hello, world!")));
     call_static_closure(cl_box);
 }

src/test/run-pass/unboxed-closures-extern-fn-hr.rs

@@ -10,11 +10,6 @@
 
 // Checks that higher-ranked extern fn pointers implement the full range of Fn traits.
 
-
-#![feature(unboxed_closures, core)]
-
-use std::ops::{Fn,FnMut,FnOnce};
-
 fn square(x: &isize) -> isize { (*x) * (*x) }
 
 fn call_it<F:Fn(&isize)->isize>(f: &F, x: isize) -> isize {
@@ -22,7 +17,7 @@ fn call_it<F:Fn(&isize)->isize>(f: &F, x: isize) -> isize {
 }
 
 fn call_it_boxed(f: &Fn(&isize) -> isize, x: isize) -> isize {
-    f.call((&x,))
+    f(&x)
 }
 
 fn call_it_mut<F:FnMut(&isize)->isize>(f: &mut F, x: isize) -> isize {

src/test/run-pass/unboxed-closures-fn-as-fnmut-and-fnonce.rs

@@ -12,7 +12,7 @@
 // any Fn trait to be used where Fn is implemented.
 
 
-#![feature(unboxed_closures, core)]
+#![feature(unboxed_closures, fn_traits)]
 
 use std::ops::{Fn,FnMut,FnOnce};
 

src/test/run-pass/unboxed-closures-fnmut-as-fnonce.rs

@@ -12,9 +12,7 @@
 // FnMut or FnOnce to be used where FnMut is implemented.
 
 
-#![feature(unboxed_closures, core)]
-
-use std::ops::{FnMut,FnOnce};
+#![feature(unboxed_closures, fn_traits)]
 
 struct S;
 

src/test/run-pass/unboxed-closures-infer-recursive-fn.rs

@@ -8,8 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(core,unboxed_closures)]
+#![feature(fn_traits, unboxed_closures)]
 
 use std::marker::PhantomData;
 

src/test/run-pass/unboxed-closures-manual-impl.rs

@@ -8,10 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![feature(unboxed_closures, core)]
-
-use std::ops::FnMut;
+#![feature(unboxed_closures, fn_traits)]
 
 struct S;
 

src/test/run-pass/unboxed-closures-monomorphization.rs

@@ -11,30 +11,25 @@
 // Test that unboxed closures in contexts with free type parameters
 // monomorphize correctly (issue #16791)
 
-#![allow(unknown_features)]
-#![feature(box_syntax)]
-#![feature(unboxed_closures, core)]
-
 fn main(){
     fn bar<'a, T:Clone+'a> (t: T) -> Box<FnMut()->T + 'a> {
-        // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
         Box::new(move || t.clone())
     }
 
     let mut f = bar(42_u32);
-    assert_eq!(f.call_mut(()), 42);
+    assert_eq!(f(), 42);
 
     let mut f = bar("forty-two");
-    assert_eq!(f.call_mut(()), "forty-two");
+    assert_eq!(f(), "forty-two");
 
     let x = 42_u32;
     let mut f = bar(&x);
-    assert_eq!(f.call_mut(()), &x);
+    assert_eq!(f(), &x);
 
     #[derive(Clone, Copy, Debug, PartialEq)]
     struct Foo(usize, &'static str);
 
     let x = Foo(42, "forty-two");
     let mut f = bar(x);
-    assert_eq!(f.call_mut(()), x);
+    assert_eq!(f(), x);
 }

src/test/run-pass/unboxed-closures-prelude.rs

@@ -12,14 +12,9 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
-#![feature(box_syntax)]
-#![feature(unboxed_closures, core)]
-
 fn main() {
-    // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
     let task: Box<Fn(isize) -> isize> = Box::new(|x| x);
-    task.call((0, ));
+    task(0);
 
     let mut task: Box<FnMut(isize) -> isize> = Box::new(|x| x);
     task(0);

src/test/run-pass/vec-macro-no-std.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(lang_items, start, no_std, core_slice_ext, libc, collections)]
+#![feature(lang_items, start, libc, collections)]
 #![no_std]
 
 extern crate std as other;
@@ -18,8 +18,6 @@ extern crate libc;
 #[macro_use]
 extern crate collections;
 
-use core::option::Option::Some;
-use core::slice::SliceExt;
 use collections::vec::Vec;
 
 // Issue #16806

src/test/rustdoc/issue-15318.rs

@@ -11,7 +11,6 @@
 // aux-build:issue-15318.rs
 // ignore-cross-compile
 
-#![feature(no_std)]
 #![no_std]
 
 extern crate issue_15318;

src/test/rustdoc/issue-23511.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(no_std, lang_items, core)]
+#![feature(lang_items)]
 #![no_std]
 
 pub mod str {