Analyser does not report invalid enumeration members

The analyzer accepts references to enumeration members that do not exist. For example, SystemSymbol.XXXXX produces no analysis error, and running the application then fails with an error saying that the enumeration has no such member.

Invalid enumeration member names should be reported during analysis and prevent compilation, for both built-in and user-defined enumerations. Valid member names must continue to work regardless of letter casing.