auto merge of #10021 : alexcrichton/rust/asm-now-analyzed-correctly, r=luqmana

We got a snapshot, taking care of a note to myself.

Author: bors

src/libstd/rt/context.rs

@@ -391,58 +391,54 @@ pub unsafe fn record_sp_limit(limit: uint) {
 /// As with the setter, this function does not have a __morestack header and can
 /// therefore be called in a "we're out of stack" situation.
 #[inline(always)]
-// NOTE: after the next snapshot, can remove the initialization before inline
-//       assembly due to an improvement in how it's handled, then this specific
-//       allow directive should get removed.
-#[allow(dead_assignment)]
 pub unsafe fn get_sp_limit() -> uint {
     return target_get_sp_limit();
 
     // x86-64
     #[cfg(target_arch = "x86_64", target_os = "macos")] #[inline(always)]
     unsafe fn target_get_sp_limit() -> uint {
-        let mut limit: uint = 0;
+        let limit;
         asm!("movq $$0x60+90*8, %rsi
               movq %gs:(%rsi), $0" : "=r"(limit) :: "rsi" : "volatile");
         return limit;
     }
     #[cfg(target_arch = "x86_64", target_os = "linux")] #[inline(always)]
     unsafe fn target_get_sp_limit() -> uint {
-        let mut limit: uint = 0;
+        let limit;
         asm!("movq %fs:112, $0" : "=r"(limit) ::: "volatile");
         return limit;
     }
     #[cfg(target_arch = "x86_64", target_os = "win32")] #[inline(always)]
     unsafe fn target_get_sp_limit() -> uint {
-        let mut limit: uint = 0;
+        let limit;
         asm!("movq %gs:0x28, $0" : "=r"(limit) ::: "volatile");
         return limit;
     }
     #[cfg(target_arch = "x86_64", target_os = "freebsd")] #[inline(always)]
     unsafe fn target_get_sp_limit() -> uint {
-        let mut limit: uint = 0;
+        let limit;
         asm!("movq %fs:24, $0" : "=r"(limit) ::: "volatile");
         return limit;
     }
 
     // x86
     #[cfg(target_arch = "x86", target_os = "macos")] #[inline(always)]
     unsafe fn target_get_sp_limit() -> uint {
-        let mut limit: uint = 0;
+        let limit;
         asm!("movl $$0x48+90*4, %eax
               movl %gs:(%eax), $0" : "=r"(limit) :: "eax" : "volatile");
         return limit;
     }
     #[cfg(target_arch = "x86", target_os = "linux")]
     #[cfg(target_arch = "x86", target_os = "freebsd")] #[inline(always)]
     unsafe fn target_get_sp_limit() -> uint {
-        let mut limit: uint = 0;
+        let limit;
         asm!("movl %gs:48, $0" : "=r"(limit) ::: "volatile");
         return limit;
     }
     #[cfg(target_arch = "x86", target_os = "win32")] #[inline(always)]
     unsafe fn target_get_sp_limit() -> uint {
-        let mut limit: uint = 0;
+        let limit;
         asm!("movl %fs:0x14, $0" : "=r"(limit) ::: "volatile");
         return limit;
     }