[Ada] Failure to detect trivial infinite recursion

[Ada] Failure to detect trivial infinite recursion

This patch includes delay statements in the set of control flow
statements since their expressions may have side effects, which in turn
may affect an infinite recursion.

2019-07-05  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/

	* sem_res.adb (Is_Control_Flow_Statement): Delay statements
	contain an expression, which in turn may have side effects and
	affect the infinite recursion. As a result, delay statements
	should not be treated specially.

From-SVN: r273118