ada: Streamline propagation of controlled flags on types

ada: Streamline propagation of controlled flags on types

The front-end maintains a set of 4 flags on (base) types that are used to
parameterize the implementation of controlled operations, and these flags
need to be propagated through composition and derivation.  This is done
on a per-flag basis in the current implementation with a few loopholes.

This introduces a Propagate_Controlled_Flags routine to that effect, which
is modeled on the existing Propagate_Concurrent_Flags routine, and is used
in most cases to do the propagation.  This also removes the handling of the
Finalize_Storage_Only flag from Inherit_Aspects_At_Freeze_Point, since the
associated aspect does not exist (only the pragma does).

gcc/ada/

	* freeze.adb (Freeze_Array_Type): Call Propagate_Controlled_Flags
	to propagate the controlled flags from the component to the array.
	(Freeze_Record_Type): Propagate the Finalize_Storage_Only flag
	from the components to the record.
	* sem_ch3.adb (Analyze_Private_Extension_Declaration): Do not call
	Propagate_Concurrent_Flags here but...
	(Array_Type_Declaration): Tidy and call Propagate_Controlled_Flags
	to propagate the controlled flags from the component to the array.
	(Build_Derived_Private_Type): Do not propagate the controlled flags
	manually here but...
	(Build_Derived_Record_Type): ...call Propagate_Controlled_Flags to
	propagate the controlled flags from parent to derived type.
	(Build_Derived_Type): Likewise.
	(Copy_Array_Base_Type_Attributes): Call Propagate_Controlled_Flags
	to copy the controlled flags.
	(Record_Type_Definition): Streamline the propagation of the
	Finalize_Storage_Only flag from the components to the record.
	* sem_ch7.adb (Preserve_Full_Attributes): Use Full_Base and call
	Propagate_Controlled_Flags to copy the controlled flags.
	* sem_ch9.adb (Analyze_Protected_Definition): Use canonical idiom
	to compute Has_Controlled_Component.
	(Analyze_Protected_Type_Declaration): Minor tweak.
	* sem_ch13.adb (Inherit_Aspects_At_Freeze_Point): Do not deal with
	Finalize_Storage_Only here.
	* sem_util.ads (Propagate_Controlled_Flags): New declaration.
	* sem_util.adb (Propagate_Controlled_Flags): New procedure.