* g++.dg/ext/visibility/pragma-override1.C: Mark as requiring
	'internal' visibility.
	* g++.dg/ext/visibility/pragma-override2.C: Likewise.
	* g++.dg/ext/visibility/visibility-7.C: Mark as requiring
	'protected' visibility.
	* gcc.dg/visibility-7.c: Likewise.
	* lib/target-supports.exp (check_visibility_available): Take
	a parameter, the kind of visibility to check for.
	* lib/target-supports-dg.exp (dg-require-visibility): Pass parameter
	to check_visibility_available.

From-SVN: r97031