This basically finishes the concrete generics implementation. We can now
enumerate all members of a concrete generic type with full type
substitution implemented.
Also add a simple test to verify that we can obtain the correct type for
a field of a concrete generic type.
This has been a little TODO for a while, and happily it's easy enough to
implement with TypeRef arrays.
Also implement ImplementedInterfaces for generic type instances via
substitution.
With this patch, generic parameters in BaseType and method param/return
types are substituted correctly and deeply. Next up will be to apply the
same substitution rules to fields, properties, events, ...
In order to select the correct generic type, model.GetGenericMethod is
changed to use Name (which includes generic parameters) instead of
BaseName. The tests for GenericMethodDefinitionInGenericClass* are also
changed to reflect the fact that the chosen methods are fully concrete.
TestGenerics now passes in its entirety.
