[mips] Switch asm to __asm__ for non-GNU compiles.

Summary:
Using asm works fine for gnu11, but fails if the compiler uses C11.
Switch to the more consistent __asm__, since that is what the rest of
the source is using.

Reviewers: petarj

Reviewed By: petarj

Subscribers: llvm-commits, sdardis, arichardson, pirama

Differential Revision: https://reviews.llvm.org/D35756

llvm-svn: 308922

compiler-rt/lib/builtins/clear_cache.c

@@ -41,7 +41,7 @@ uintptr_t GetCurrentProcess(void);
      * clear_mips_cache - Invalidates instruction cache for Mips.
      */
     static void clear_mips_cache(const void* Addr, size_t Size) {
-      asm volatile (
+      __asm__ volatile (
         ".set push\n"
         ".set noreorder\n"
         ".set noat\n"