ada: Refactor repeated code for querying Boolean-valued aspects

ada: Refactor repeated code for querying Boolean-valued aspects

Code cleanup following a fix for aspect Exclusive_Functions; semantics
is unaffected.

gcc/ada/

	* exp_ch9.adb (Build_Protected_Subprogram_Body,
	Build_Protected_Subprogram_Call_Cleanup): Reuse refactored
	routine.
	* sem_util.adb
	(Has_Enabled_Aspect): Refactored repeated code.
	(Is_Static_Function): Reuse refactored routine.
	* sem_util.ads (Has_Enabled_Aspect):
	New query routine refactored from repeated code.