IsA with generic type parameter can crash at runtime

Using IsA with a generic method type parameter could compile but fail at runtime. The reported form was T IsA Person inside generic code. The related value IsA T form also needed to resolve T to the concrete runtime generic type argument.

Expected behaviour:

IsA should use the concrete generic type argument at runtime, or the compiler should reject unsupported syntax. It should not crash or perform a normal global lookup for the type parameter name.