This patch corrects the generation of dynamic accessibility checks which
are guaranteed to trigger errors during run time so as to give the user
proper warning during unit compiliation.

2019-07-11  Justin Squirek  <squirek@adacore.com>

gcc/ada/

	* checks.adb (Apply_Accessibility_Check): Add check for constant
	folded conditions on accessibility checks.

gcc/testsuite/

	* gnat.dg/access7.adb: New testcase.

From-SVN: r273381