auto merge of #17268 : aturon/rust/mut-conventions, r=alexcrichton

As per [RFC 52](https://github.com/rust-lang/rfcs/blob/master/active/0052-ownership-variants.md), use `_mut` suffixes to mark mutable variants, and `into_iter` for moving iterators. Additional details and motivation in the RFC.

Note that the iterator *type* names are not changed by this RFC; those are awaiting a separate RFC for standardization.

Closes #13660
Closes #16810

[breaking-change]

2 files changed, 5 insertions, 5 deletions

diff --git a/src/liballoc/heap.rs b/src/liballoc/heap.rs
index 2905b30deeb..51e1f64e006 100644
--- a/src/liballoc/heap.rs
+++ b/src/liballoc/heap.rs
@@ -140,7 +140,7 @@ static MIN_ALIGN: uint = 16;
 #[cfg(jemalloc)]
 mod imp {
     use core::option::{None, Option};
-    use core::ptr::{RawPtr, mut_null, null};
+    use core::ptr::{RawPtr, null_mut, null};
     use core::num::Int;
     use libc::{c_char, c_int, c_void, size_t};
     use super::MIN_ALIGN;
@@ -230,7 +230,7 @@ mod imp {
 
     pub fn stats_print() {
         unsafe {
-            je_malloc_stats_print(None, mut_null(), null())
+            je_malloc_stats_print(None, null_mut(), null())
         }
     }
 }
diff --git a/src/liballoc/libc_heap.rs b/src/liballoc/libc_heap.rs
index e3fa639929f..4f6400630fd 100644
--- a/src/liballoc/libc_heap.rs
+++ b/src/liballoc/libc_heap.rs
@@ -12,7 +12,7 @@
 //! The global (exchange) heap.
 
 use libc::{c_void, size_t, free, malloc, realloc};
-use core::ptr::{RawPtr, mut_null};
+use core::ptr::{RawPtr, null_mut};
 
 /// A wrapper around libc::malloc, aborting on out-of-memory.
 #[inline]
@@ -20,7 +20,7 @@ pub unsafe fn malloc_raw(size: uint) -> *mut u8 {
     // `malloc(0)` may allocate, but it may also return a null pointer
     // http://pubs.opengroup.org/onlinepubs/9699919799/functions/malloc.html
     if size == 0 {
-        mut_null()
+        null_mut()
     } else {
         let p = malloc(size as size_t);
         if p.is_null() {
@@ -37,7 +37,7 @@ pub unsafe fn realloc_raw(ptr: *mut u8, size: uint) -> *mut u8 {
     // http://pubs.opengroup.org/onlinepubs/9699919799/functions/realloc.html
     if size == 0 {
         free(ptr as *mut c_void);
-        mut_null()
+        null_mut()
     } else {
         let p = realloc(ptr as *mut c_void, size as size_t);
         if p.is_null() {