Don't include mm_malloc.h in test, it pulls in system headers on msvc.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160122 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/rdrand-builtins.c b/test/CodeGen/rdrand-builtins.c
index 4263502..bd4f2cf 100644
--- a/test/CodeGen/rdrand-builtins.c
+++ b/test/CodeGen/rdrand-builtins.c
@@ -1,6 +1,9 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -target-feature +rdrnd -emit-llvm -S -emit-llvm -o - %s | FileCheck %s
 #include <immintrin.h>
 
+// Don't include mm_malloc.h, it's system specific.
+#define __MM_MALLOC_H
+
 int rdrand16(unsigned short *p) {
   return _rdrand16_step(p);
 // CHECK: @rdrand16