[X86][inline-asm] Add support for MS 'EVEN' directive

[coby]

Summary

MS assembly syntax provide us with the 'EVEN' directive as a synonymous to at&t '.even'.
This patch include the (small, simple) changes need to allow it.

Test is provided at the following (clang-side) review:
https://reviews.llvm.org/D27418

Differential Revision: https://reviews.llvm.org/D27417

[m_zuckerman]

lgtm

llvm/trunk/lib/MC/MCParser/AsmParser.cpp

bool AsmParser::parseStatement(ParseStatementInfo &Info,
   if (ParsingInlineAsm && (IDVal == "_emit" || IDVal == "__emit" ||
                            IDVal == "_EMIT" || IDVal == "__EMIT"))
     return parseDirectiveMSEmit(IDLoc, Info, IDVal.size());
 
   // __asm align
   if (ParsingInlineAsm && (IDVal == "align" || IDVal == "ALIGN"))
     return parseDirectiveMSAlign(IDLoc, Info);
 
-  if (ParsingInlineAsm && (IDVal == "even"))
+  if (ParsingInlineAsm && (IDVal == "even" || IDVal == "EVEN"))
     Info.AsmRewrites->emplace_back(AOK_EVEN, IDLoc, 4);
   if (checkForValidSection())
     return true;
 
   // Canonicalize the opcode to lower case.
   std::string OpcodeStr = IDVal.lower();
   ParseInstructionInfo IInfo(Info.AsmRewrites);
   bool ParseHadError = getTargetParser().ParseInstruction(IInfo, OpcodeStr, ID,