re PR c++/25342 (internal compiler error: in lookup_member, at cp/search.c:1209)

re PR c++/25342 (internal compiler error: in lookup_member, at cp/search.c:1209)

	PR c++/25342
	* cp-tree.h (DECL_TEMPLATE_SPECIALIZATIONS): Revise
	documentation.
	* pt.c (determine_specialization): Use INNERMOST_TEMPLATE_PARMS,
	not TREE_VALUE.
	(instantiate_class_template): Simplify.
	(verify_class_unification): Remove.
	(unify): Document parameters.  Use INNERMOST_TEMPLATE_ARGS to
	permit multiple levels of template arguments.
	(more_specialized_class): Simplify.
	(get_class_bindings): Pass full arguments to unify.  Fold
	verify_class_unification into this function.  Return full
	arguments.
	(most_specialized_class): Adjust for changes to
	get_class_bindings.  Issue errors here for ambiguity.  Return the
	fully deduced arguments for the most specialized class, in
	addition to the partial specialization.
	PR c++/25342
	* g++.gd/template/partial4.C: New test.

From-SVN: r110466