PR c++/81124
	PR c++/79766
	* name-lookup.c (set_decl_namespace): Don't follow using
	directives and ignore using decls.  Only check overly-explicit
	scope after discovering decl.

	* g++.dg/lookup/pr79766.C: New.
	* g++.dg/lookup/pr81124.C: New.
	* g++.dg/template/explicit6.C: Adjust.
	* g++.old-deja/g++.other/decl5.C: Adjust.

From-SVN: r249385