* call.c (joust): Don't warn about "confusing" conversions to the
	same type.
	* class.c (push_nested_class): Complain about namespaces.
	* decl.c (start_decl): Enter the object's namespace.
	(cp_finish_decl): Leave it.
	(grokdeclarator): Likewise.
	* decl2.c (check_decl_namespace): New function.
	(finish_file): Call it.
	* parse.y (complex_direct_notype_declarator): Set complexity
	of namespace-qualified ids to -1, enter the namespace.
	* method.c (build_template_decl_overload): Expect _DECL as first
	parameter. Put context temporarily into current_namespace.
	* pt.c (check_explicit_specialization): Change caller.
	(tsubst): Likewise.
	* init.c (build_offset_ref): Call mark_used and
	convert_from_reference for namespace members.

From-SVN: r21135