Symbols that had the TypeParam flag set were classified as alias types unless they also had
the Deferred flag set. Maybe this did not break that much since Namer always added the Deferred
for type parameters. But export forwarders use synthesized parameters which did not have Deferred
set.

There were some other occurrences of isAbstractType where it was not clear why
type parameters should be excluded. Use isAbstractOrParamType as the new default.

Always use isAbstractorParamType. quotes.reflect still uses isAbstractType for backwards compatibility,
but it now also includes type parameters. This was the case anyway before for type parameters set up by
Namer.