[ms-inline asm] Accept the emit directive as either _emit or __emit.

llvm-svn: 174998
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 4d6756e1..a4b4a54 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -1446,8 +1446,8 @@
     return Error(IDLoc, "unknown directive");
   }
 
-  // _emit
-  if (ParsingInlineAsm && IDVal == "_emit")
+  // _emit or __emit
+  if (ParsingInlineAsm && (IDVal == "_emit" || IDVal == "__emit"))
     return ParseDirectiveEmit(IDLoc, Info);
 
   CheckForValidSection();