[COFF, ARM64] Add MS builtins __dmb, __dsb, __isb

Differential Revision: https://reviews.llvm.org/D38821

llvm-svn: 315567
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index e915d36..f58bf9f 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -27,6 +27,8 @@
 
 #define BUILTIN(ID, TYPE, ATTRS)                                               \
    {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr},
+#define LANGBUILTIN(ID, TYPE, ATTRS, LANG)                                     \
+  {#ID, TYPE, ATTRS, nullptr, LANG, nullptr},
 #include "clang/Basic/BuiltinsAArch64.def"
 };