Update infrastructure for fail -> panic

This includes updating the language items and marking what needs to
change after a snapshot.

If you do not use the standard library, the language items you need to
implement have changed. For example:

```rust
 #[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
```

is now

```rust
 #[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }
```

Related, lesser-implemented language items `fail` and
`fail_bounds_check` have become `panic` and `panic_bounds_check`, as
well. These are implemented by `libcore`, so it is unlikely (though
possible!) that these two renamings will affect you.

[breaking-change]

Fix test suite

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

@@ -14,8 +14,8 @@
 #[lang="sized"]
 pub trait Sized for Sized? {}
 
-#[lang="fail"]
-fn fail(_: &(&'static str, &'static str, uint)) -> ! { loop {} }
+#[lang="panic"]
+fn panic(_: &(&'static str, &'static str, uint)) -> ! { loop {} }
 
 #[lang = "stack_exhausted"]
 extern fn stack_exhausted() {}

src/test/compile-fail/binop-fail-3.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-fn foo() -> ! { fail!("quux"); }
+fn foo() -> ! { panic!("quux"); }
 fn main() {
     foo() //~ ERROR the type of this value must be known in this context
     ==

src/test/compile-fail/issue-5500.rs

@@ -9,6 +9,6 @@
 // except according to those terms.
 
 fn main() {
-    &fail!()
+    &panic!()
     //~^ ERROR mismatched types: expected `()`, found `&<generic #2>` (expected (), found &-ptr)
 }

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

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 // aux-build:weak-lang-items.rs
-// error-pattern: language item required, but not found: `fail_fmt`
+// error-pattern: language item required, but not found: `panic_fmt`
 // error-pattern: language item required, but not found: `stack_exhausted`
 // error-pattern: language item required, but not found: `eh_personality`
 

src/test/run-fail/assert-macro-explicit.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'assertion failed: false'
+// error-pattern:panicked at 'assertion failed: false'
 
 fn main() {
     assert!(false);

src/test/run-fail/assert-macro-fmt.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'test-assert-fmt 42 rust'
+// error-pattern:panicked at 'test-assert-fmt 42 rust'
 
 fn main() {
     assert!(false, "test-assert-fmt {} {}", 42i, "rust");

src/test/run-fail/assert-macro-owned.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'test-assert-owned'
+// error-pattern:panicked at 'test-assert-owned'
 
 fn main() {
     assert!(false, "test-assert-owned".to_string());

src/test/run-fail/assert-macro-static.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'test-assert-static'
+// error-pattern:panicked at 'test-assert-static'
 
 fn main() {
     assert!(false, "test-assert-static");

src/test/run-fail/by-value-self-objects-fail.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:explicit failure
+// error-pattern:explicit panic
 
 trait Foo {
     fn foo(self, x: int);

src/test/run-fail/expr-fn-fail.rs

@@ -8,10 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// error-pattern:explicit panic
 
-
-
-// error-pattern:explicit failure
 fn f() -> ! { panic!() }
 
 fn main() { f(); }

src/test/run-fail/expr-if-fail-fn.rs

@@ -8,10 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// error-pattern:explicit panic
 
-
-
-// error-pattern:explicit failure
 fn f() -> ! { panic!() }
 
 fn g() -> int { let x = if true { f() } else { 10 }; return x; }

src/test/run-fail/expr-if-fail.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// error-pattern:explicit panic
 
-
-
-// error-pattern:explicit failure
 fn main() { let _x = if false { 0i } else if true { panic!() } else { 10i }; }

src/test/run-fail/expr-match-fail-fn.rs

@@ -8,10 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// error-pattern:explicit panic
 
-
-
-// error-pattern:explicit failure
 fn f() -> ! { panic!() }
 
 fn g() -> int { let x = match true { true => { f() } false => { 10 } }; return x; }

src/test/run-fail/expr-match-fail.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// error-pattern:explicit panic
 
-
-
-// error-pattern:explicit failure
 fn main() { let _x = match true { false => { 0i } true => { panic!() } }; }

src/test/run-fail/fail-macro-any-wrapped.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'Box<Any>'
+// error-pattern:panicked at 'Box<Any>'
 
 fn main() {
     panic!(box 612_i64);

src/test/run-fail/fail-macro-any.rs

@@ -8,8 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'Box<Any>'
-
+// error-pattern:panicked at 'Box<Any>'
 
 fn main() {
     panic!(box 413i as Box<::std::any::Any+Send>);

src/test/run-fail/fail-macro-explicit.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'explicit failure'
+// error-pattern:panicked at 'explicit panic'
 
 fn main() {
     panic!();

src/test/run-fail/fail-macro-fmt.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'test-fail-fmt 42 rust'
+// error-pattern:panicked at 'test-fail-fmt 42 rust'
 
 fn main() {
     panic!("test-fail-fmt {} {}", 42i, "rust");

src/test/run-fail/fail-macro-owned.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'test-fail-owned'
+// error-pattern:panicked at 'test-fail-owned'
 
 fn main() {
     panic!("test-fail-owned");

src/test/run-fail/fail-macro-static.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:failed at 'test-fail-static'
+// error-pattern:panicked at 'test-fail-static'
 
 fn main() {
     panic!("test-fail-static");

src/test/run-fail/fail-non-utf8.rs

@@ -12,7 +12,7 @@
 // Previously failed formating invalid utf8.
 // cc #16877
 
-// error-pattern:failed at 'hello<6C>'
+// error-pattern:panicked at 'hello<6C>'
 
 struct Foo;
 impl std::fmt::Show for Foo {

src/test/run-fail/fail-task-name-none.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:task '<unnamed>' failed at 'test'
+// error-pattern:task '<unnamed>' panicked at 'test'
 
 use std::task;
 

src/test/run-fail/fail-task-name-owned.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:task 'owned name' failed at 'test'
+// error-pattern:task 'owned name' panicked at 'test'
 
 use std::task::TaskBuilder;
 

src/test/run-fail/fail-task-name-send-str.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:task 'send name' failed at 'test'
+// error-pattern:task 'send name' panicked at 'test'
 
 fn main() {
     let r: Result<int,_> =

src/test/run-fail/fail-task-name-static.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:task 'static name' failed at 'test'
+// error-pattern:task 'static name' panicked at 'test'
 
 fn main() {
     let r: Result<int,_> =

src/test/run-fail/glob-use-std.rs

@@ -14,7 +14,7 @@
 //
 // Expanded pretty printing causes resolve conflicts.
 
-// error-pattern:fail works
+// error-pattern:panic works
 #![feature(globs)]
 
 use std::*;

src/test/run-fail/issue-12920.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:explicit failure
+// error-pattern:explicit panic
 
 pub fn main() {
     panic!(); println!("{}", 1i);

src/test/run-fail/issue-2444.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:explicit failure
+// error-pattern:explicit panic
 
 use std::sync::Arc;
 

src/test/run-fail/main-fail.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:task '<main>' failed at
+// error-pattern:task '<main>' panicked at
 
 fn main() {
     panic!()

src/test/run-fail/match-bot-fail.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:explicit failure
+// error-pattern:explicit panic
 
 #![allow(unreachable_code)]
 #![allow(unused_variable)]

src/test/run-fail/native-failure.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 // ignore-android (FIXME #11419)
-// error-pattern:explicit failure
+// error-pattern:explicit panic
 
 extern crate native;
 

src/test/run-fail/test-fail.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 // check-stdout
-// error-pattern:task 'test_foo' failed at
+// error-pattern:task 'test_foo' panicked at
 // compile-flags: --test
 // ignore-pretty: does not work well with `--test`
 

src/test/run-fail/unique-fail.rs

@@ -8,5 +8,5 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern: fail
+// error-pattern: panic
 fn main() { box panic!(); }

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

@@ -19,4 +19,4 @@ pub extern fn bar() {}
 
 #[lang = "stack_exhausted"] fn stack_exhausted() {}
 #[lang = "eh_personality"] fn eh_personality() {}
-#[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
+#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }

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

@@ -19,4 +19,4 @@ pub extern fn foo() {}
 
 #[lang = "stack_exhausted"] fn stack_exhausted() {}
 #[lang = "eh_personality"] fn eh_personality() {}
-#[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
+#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }

src/test/run-pass/smallest-hello-world.rs

@@ -22,7 +22,7 @@ extern "rust-intrinsic" { fn transmute<T, U>(t: T) -> U; }
 
 #[lang = "stack_exhausted"] extern fn stack_exhausted() {}
 #[lang = "eh_personality"] extern fn eh_personality() {}
-#[lang = "fail_fmt"] fn fail_fmt() -> ! { loop {} }
+#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }
 
 #[start]
 #[no_stack_check]