[Ada] Front-end support for Storage_Model feature

[Ada] Front-end support for Storage_Model feature

gcc/ada/

	* aspects.ads (type Aspect_Id): Add
	Aspect_Designated_Storage_Model and Aspect_Storage_Model_Type.
	(Aspect_Argument): Add associations for the above new aspects.
	(Is_Representation_Aspect): Likewise.
	(Aspect_Names, Aspect_Delay): Likewise.
	* exp_ch4.adb (Expand_N_Allocator): Call Find_Storage_Op rather
	than Find_Prim_Op.
	* exp_intr.adb (Expand_Unc_Deallocation): Likewise.
	* exp_util.ads (Find_Storage_Op): New function that locates
	either a primitive operation of a storage pool or an operation
	of a storage-model type specified in its Storage_Model_Type
	aspect.
	* exp_util.adb (Find_Storage_Op): New function that calls either
	Find_Prim_Op or Get_Storage_Model_Type_Entity to locate a
	storage-related operation that is associated with a type.
	* sem_ch13.adb (Analyze_Aspects_At_Freeze_Point): Analyzes,
	resolves, and validates the arguments of aspect
	Designated_Storage_Model_Type.
	(Analyze_Aspect_Specifications): Sets delay-related flags on
	storage-model aspects when Delay_Required. Checks that aspect
	Designated_Storage_Model is only specified for an access type
	and that aspect Storage_Model_Type is only specified on an
	immutably limited type. Also records such aspects for their
	associated types.
	(Check_Aspect_At_Freeze_Point): Resolve each of the argument
	associations given for a Storage_Model_Type aspect.
	(Resolve_Storage_Model_Type_Argument): New procedure that
	resolves an argument given in the association for a given entity
	name associated with a type with aspect Storage_Model_Type,
	ensuring that it has the proper kind or profile.
	(Validate_Storage_Model_Type_Aspect): New procedure that checks
	the legality and completeness of the entity associations given
	in a Storage_Model_Type aspect.
	* sem_util.ads (package Storage_Model_Support): New nested
	package that encapsulates a set of convenient utility functions
	for retrieving entities, etc. associated with
	storage-model-related types and objects.
	(Get_Storage_Model_Type_Entity): New function to return a
	specified entity associated with a type that has aspect
	Storage_Model_Type.
	(Has_Designated_Storage_Model_Aspect): New function that returns
	whether a type has aspect Designated_Storage_Model.
	(Has_Storage_Model_Type_Aspect): New function that returns
	whether a type has aspect Storage_Model_Type.
	(Storage_Model_Object): New function that returns the object
	Entity_Id associated with a type's Designated_Storage_Model
	aspect.
	(Storage_Model_Type): New function that returns the type
	associated with a storage-model object (when the object's type
	specifies Storage_Model_Type).
	(Storage_Model_Address_Type): New function that returns the
	Address_Type associated with a type that has aspect
	Storage_Model_Type.
	(Storage_Model_Null_Address): New function that returns the
	Null_Address constant associated with a type that has aspect
	Storage_Model_Type.
	(Storage_Model_Allocate): New function that returns the Allocate
	procedure associated with a type that has aspect
	Storage_Model_Type.
	(Storage_Model_Deallocate): New function that returns the
	Deallocate procedure associated with a type that has aspect
	Storage_Model_Type.
	(Storage_Model_Copy_From): New function that returns the
	Copy_From procedure associated with a type that has aspect
	Storage_Model_Type.
	(Storage_Model_Copy_To): New function that returns the Copy_To
	procedure associated with a type that has aspect
	Storage_Model_Type.
	(Storage_Model_Storage_Size): New function that returns the
	Storage_Size function associated with a type that has aspect
	Storage_Model_Type.
	* sem_util.adb (package Storage_Model_Support): Body of new
	nested package that contains the implementations the utility
	functions declared in the spec of this package.
	* snames.ads-tmpl: Add new names Name_Designated_Storage_Pool,
	Name_Storage_Model, Name_Storage_Model_Type, Name_Address_Type,
	Name_Copy_From, Name_Copy_To, and Name_Null_Address for the new
	aspects and associated aspect arguments.