2017-01-06  Ed Schonberg  <schonberg@adacore.com>

	* exp_ch5.adb (Get_Default_Iterator): For a derived type, the
	alias of the inherited op is the parent iterator, no need to
	examine dispatch table positions which might not be established
	yet if type is not frozen.
	* sem_disp.adb (Check_Controlling_Formals): The formal of a
	predicate function may be a subtype of a tagged type.
	* sem_ch3.adb (Complete_Private_Subtype): Adjust inheritance
	of representation items for the completion of a type extension
	where a predicate applies to the partial view.
	* checks.ads, checks.adb (Apply_Predicate_Check): Add optional
	parameter that designates function whose actual receives a
	predicate check, to improve warning message when the check will
	lead to infinite recursion.
	* sem_res.adb (Resolve_Actuals): Pass additional parameter to
	Apply_Predicate_Check.

From-SVN: r244132