MIR Serialization: Serialize the metadata machine operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242916 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MIRParser/MILexer.cpp

@@ -310,6 +310,8 @@ static MIToken::TokenKind symbolToken(char C) {
     return MIToken::equal;
   case ':':
     return MIToken::colon;
+  case '!':
+    return MIToken::exclaim;
   default:
     return MIToken::Error;
   }