* doc/invoke.texi (-Wno-prio-ctor-dtor): Document new warning
	-Wno-prio-ctor-dtor.

	* c-attribs.c (get_priority): Add a warning flag warn_prio_ctor_dtor
	to generate constructor destructor priority warning.
	* c.opt (-Wprio-ctor-dtor): New option.

	* c-c++-common/Wprio-ctor-dtor.c: New test.

From-SVN: r264853