model loader #1156: pretend raw types have Object type arguments

otherwise their type is invalid
type mirrors #1156: support accessing upper bounds for type variables
model loader #1156: added a mode to obtainType where we generate types based on the TP bounds

which we then use to get proper types for raw type arguments
updated test for #1156
enabled test for #1156
model loader #1156: detect recursive type parameter bounds when generating raw type arguments

and replace them with Object
updated test for #1156 to test recursive type bounds