MIR Serialization: Serialize the sub register indices.

This commit serializes the sub register indices from the register machine
operands.

Reviewers: Duncan P. N. Exon Smith


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242084 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MIRParser/MILexer.cpp

@@ -179,6 +179,8 @@ static MIToken::TokenKind symbolToken(char C) {
     return MIToken::comma;
   case '=':
     return MIToken::equal;
+  case ':':
+    return MIToken::colon;
   default:
     return MIToken::Error;
   }