fix up a couple mono-binds-related tests

mono-binds/test03 is no longer a really relevant test since mono-binds
doesn't do any generalization. However I fixed up the type signature
and updated the output in case it becomes relevant again in the
future.

issues/issue225 is fine, but work on the master branch increased the
verbosity of constraint solver failures when mono-binds is off. It
still works fine when we monomorphize the local definition.