PR c++/89744 - ICE with specialization of member class template.

PR c++/89744 - ICE with specialization of member class template.

My fix five years ago for PR 60241 was incomplete: when we reassign implicit
instances of a partial instantiation of a member template to the explicit
specialization of that partial instantiation, we also need to adjust the
CLASSTYPE_TI_ARGS to match what we'd get when looking up that instance after
the explicit specialization.  We also need to do this when we later look up
the instance in a way that only finds the explicit specialization halfway
through lookup_template_class_1.

	* pt.c (lookup_template_class_1): If the partial instantiation is
	explicitly specialized, adjust.
	(maybe_process_partial_specialization): Also adjust
	CLASSTYPE_TI_ARGS.

From-SVN: r270036