sem_ch8.adb (Available_Subtype): Optimization in Find_Selected_Component...

sem_ch8.adb (Available_Subtype): Optimization in Find_Selected_Component...

2015-03-02  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch8.adb (Available_Subtype): Optimization in
	Find_Selected_Component: when safe, use existing subtype of
	array component, possibly discriminant-dependent, rather than
	creating new subtype declaration for it. In this fashion different
	occurrences of the component have the same subtype, rather than
	just equivalent ones. Simplifies value tracing in GNATProve.

From-SVN: r221100