Support partial specialization of member class templates.

Support partial specialization of member class templates.

	* pt.c (get_class_bindings): Add outer_args parm.
	(most_specialized_class): Likewise.
	(instantiate_class_template): Pass it.
	(more_specialized_class): Likewise.
	(lookup_template_class): Get context from template if none
	was specified.
	(finish_member_template_decl): Don't do anything with a
	partial specialization.
	* decl2.c (check_member_template): Use IS_AGGR_TYPE instead of
	AGGREGATE_TYPE_P.
	* class.c (finish_struct): Member class templates have already been
	checked for name clashes.
	* decl.c (pushdecl_with_scope): Handle pushing at class level.

From-SVN: r18285