Calls to various Vet functions are used throughout the containers
packages to check internal consistency. This patch improves efficiency
by disabling these calls when Container_Checks are suppressed.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

	* libgnat/a-crbtgo.ads, libgnat/a-rbtgbo.ads,
	libgnat/a-cbdlli.adb, libgnat/a-cbhama.adb,
	libgnat/a-cbhase.adb, libgnat/a-cdlili.adb,
	libgnat/a-cfdlli.adb, libgnat/a-cfhama.adb,
	libgnat/a-cfhase.adb, libgnat/a-cidlli.adb,
	libgnat/a-cihama.adb, libgnat/a-cihase.adb,
	libgnat/a-cohama.adb, libgnat/a-cohase.adb,
	libgnat/a-crbtgo.adb, libgnat/a-crdlli.adb, libgnat/a-rbtgbo.adb
	(Vet): Make the Vet functions do nothing when
	Container_Checks'Enabled is False, and inline them, so the calls
	disappear when optimizing.