re PR c++/20637 (Confusing message with different using declarations)

re PR c++/20637 (Confusing message with different using declarations)

cp:
PR c++/20637
	* cp-tree.h (add_method): Add using_decl parameter.
	* class.c (add_method): Add using_decl parameter.  Adjust error
	messages.
	(handle_using_decl): Pass the using decl to add_method.
	(clone_function_decl): Adjust add_member calls.
	* decl2.c (check_classfn): Likewise.
	* method.c (lazily_declare_fn): Likewise.
	* semantics.c (finish_member_declaration): Likewise.

	* method.c (synthesize_method): Use inform, not warning.
testsuite:
	PR c++/20637
	* g++.dg/inherit/using4.C: New.
	* g++.dg/overload/error1.C: Adjust expected errors.
	* g++.old-deja/g++.benjamin/warn02.C: Likewise.
	* g++.old-deja/g++.brendan/arm2.C: Likewise.
	* g++.old-deja/g++.other/redecl2.C: Likewise.
	* g++.old-deja/g++.other/redecl4.C: Likewise.
	* g++.old-deja/g++.pt/memtemp78.C: Likewise.

From-SVN: r100664