Cleanup: Remove more old "specialization" code
Cleanup: Begin removing "isFixed"
Cleanup: Remove "isFixed"
Cleanup: Remove "_typeArguments" from base symbol type
Cleanup: Remove more old specialization infrastructure
Cleanup: Address more "GTODO" comments
Clean up some uses of specializingToAny
Cleanup: Remove more specialization state from the resolution context object
Cleanup: Remove the specialization stack from the resolution context
Cleanup: Remove more dead specialization code from the resolver
Cleanup: Remove more dead code