* pt.c (resolve_overloaded_unification): New fn.
	(try_one_overload): Likewise.
	(unify): Don't fail on unknown type.
	(type_unification_real): Likewise.  Use resolve_overloaded_unification
	to handle an overloaded argument.
	(template_args_equal): Split out...
	(comp_template_args): From here.
	(determine_specialization): Also allow a template with more
	parms than were explicitly specified.
	* cp-tree.h: Add template_args_equal.
	* call.c (resolve_args): Remove TEMPLATE_ID_EXPR code.

From-SVN: r22951