auto merge of #19617 : nikomatsakis/rust/issue-19261-2, r=nrc

**First commit.** Patch up debruijn indices. Fixes #19537. 

**Second commit.** Stop reborrowing so much. Fixes #19147. Fixes #19261.

r? @nick29581

src/test/compile-fail/borrowck-return-variable-on-stack-via-clone.rs

@@ -0,0 +1,20 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Check that when we clone a `&T` pointer we properly relate the
+// lifetime of the pointer which results to the pointer being cloned.
+// Bugs in method resolution have sometimes broken this connection.
+// Issue #19261.
+
+fn leak<'a, T>(x: T) -> &'a T {
+    (&x).clone() //~ ERROR `x` does not live long enough
+}
+
+fn main() { }

src/test/compile-fail/hrtb-debruijn-in-receiver.rs

@@ -0,0 +1,28 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test the case where the `Self` type has a bound lifetime that must
+// be adjusted in the fn signature. Issue #19537.
+
+use std::collections::HashMap;
+
+struct Foo<'a> {
+    map: HashMap<uint, &'a str>
+}
+
+impl<'a> Foo<'a> {
+    fn new() -> Foo<'a> { panic!() }
+    fn insert(&'a mut self) { }
+}
+fn main() {
+    let mut foo = Foo::new();
+    foo.insert();
+    foo.insert(); //~ ERROR cannot borrow
+}

src/test/run-pass/method-mut-self-modifies-mut-slice-lvalue.rs

@@ -0,0 +1,54 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that an `&mut self` method, when invoked on an lvalue whose
+// type is `&mut [u8]`, passes in a pointer to the lvalue and not a
+// temporary. Issue #19147.
+
+use std::raw;
+use std::mem;
+use std::slice;
+use std::io::IoResult;
+
+trait MyWriter {
+    fn my_write(&mut self, buf: &[u8]) -> IoResult<()>;
+}
+
+impl<'a> MyWriter for &'a mut [u8] {
+    fn my_write(&mut self, buf: &[u8]) -> IoResult<()> {
+        slice::bytes::copy_memory(*self, buf);
+
+        let write_len = buf.len();
+        unsafe {
+            *self = mem::transmute(raw::Slice {
+                data: self.as_ptr().offset(write_len as int),
+                len: self.len() - write_len,
+            });
+        }
+
+        Ok(())
+    }
+}
+
+fn main() {
+    let mut buf = [0_u8, .. 6];
+
+    {
+        let mut writer = buf.as_mut_slice();
+        writer.my_write(&[0, 1, 2]).unwrap();
+        writer.my_write(&[3, 4, 5]).unwrap();
+    }
+
+    // If `my_write` is not modifying `buf` in place, then we will
+    // wind up with `[3, 4, 5, 0, 0, 0]` because the first call to
+    // `my_write()` doesn't update the starting point for the write.
+
+    assert_eq!(buf, [0, 1, 2, 3, 4, 5]);
+}