Auto merge of #30975 - Manishearth:rollup, r=Manishearth

- Successful merges: #30938, #30940, #30943, #30949, #30952, #30957, #30959
- Failed merges:

2 files changed, 1 insertions, 3 deletions

diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index ffa0ec4917c..0a232ed0620 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -78,7 +78,6 @@
 #![feature(custom_attribute)]
 #![feature(fundamental)]
 #![feature(lang_items)]
-#![feature(num_bits_bytes)]
 #![feature(optin_builtin_traits)]
 #![feature(placement_in_syntax)]
 #![feature(placement_new_protocol)]
diff --git a/src/liballoc/raw_vec.rs b/src/liballoc/raw_vec.rs
index 52bd62f7a66..c407cef25e7 100644
--- a/src/liballoc/raw_vec.rs
+++ b/src/liballoc/raw_vec.rs
@@ -16,7 +16,6 @@ use super::oom;
 use super::boxed::Box;
 use core::ops::Drop;
 use core::cmp;
-use core;
 
 /// A low-level utility for more ergonomically allocating, reallocating, and deallocating a
 /// a buffer of memory on the heap without having to worry about all the corner cases
@@ -584,7 +583,7 @@ impl<T> Drop for RawVec<T> {
 
 #[inline]
 fn alloc_guard(alloc_size: usize) {
-    if core::usize::BITS < 64 {
+    if mem::size_of::<usize>() < 8 {
         assert!(alloc_size <= ::core::isize::MAX as usize,
                 "capacity overflow");
     }