MIR Serialization: Serialize the 'dead' register machine operand flag.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241624 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MIRParser/MILexer.cpp

@@ -70,6 +70,7 @@ static MIToken::TokenKind getIdentifierKind(StringRef Identifier) {
       .Case("_", MIToken::underscore)
       .Case("implicit", MIToken::kw_implicit)
       .Case("implicit-def", MIToken::kw_implicit_define)
+      .Case("dead", MIToken::kw_dead)
       .Default(MIToken::Identifier);
 }