sem_disp.adb (Is_Dynamically_Tagged): when applied to an entity or a function call...

sem_disp.adb (Is_Dynamically_Tagged): when applied to an entity or a function call, return True if type is class-wide.

2015-01-30  Ed Schonberg  <schonberg@adacore.com>

	* sem_disp.adb (Is_Dynamically_Tagged): when applied to an entity
	or a function call, return True if type is class-wide.
	* sem_res.adb (Resolve_Case_Expression, Resolve_If_Expression);
	Apply RM 4.5.7 (17/3): all or none of the dependent expression
	of a conditional expression must be dynamically tagged.

From-SVN: r220276