It seems that most of `tIdentifier` -> `Identifier` changes should not depend on lexer changes nor *NoES5. It would be nice to split them.
Unless I'm missing something, `ProprtyDefinition` could have explicit rules like `kGET ':' AssignmentExpression` instead of depending on a lexer hack. Is there anything other than labelled statements that need the lexer hack? Did you see actual code depending that?