[Ada] Ada2020: Special handling of types derived from runtime

[Ada] Ada2020: Special handling of types derived from runtime

gcc/ada/

	* einfo.ads (Is_Ada_2022_Only): Adding documentation.
	* gen_il-fields.ads (Is_Ada_2022_Only): New flag.
	* gen_il-gen-gen_entities.adb (Is_Ada_2022_Only): New flag.
	* itypes.adb (Create_Null_Excluding_Itype): Inherit
	Is_Ada_2022_Only.
	* sem_ch3.adb (Check_Abstract_Overriding): Skip reporting error
	on Ada 2022 only subprograms that require overriding if we are
	not in Ada 2022 mode.
	(Derive_Subprogram): Inherit Is_Ada_2022_Only.
	* sem_ch6.adb (Check_Overriding_Indicator): Inherit
	Is_Ada_2022_Only.
	(New_Overloaded_Entity): Inherit Is_Ada_2022_Only.
	* sem_ch7.adb (Declare_Inherited_Private_Subprograms): Inherit
	Is_Ada_2022_Only.
	(Preserve_Full_Attributes): Inherit Is_Ada_2022_Only.
	* sem_disp.adb (Find_Hidden_Overridden_Primitive): Inherit
	Is_Ada_2022_Only.
	(Override_Dispatching_Operation): Inherit Is_Ada_2022_Only.
	* sem_prag.adb (Analyze_Pragma): Allow form with argument for
	Ada 2022.
	* sem_type.adb: (Disambiguate): Deal with Is_Ada_2022_Only
	* lib-xref.adb (Generate_Reference): Error on static and
	dispatching calls to Ada 2022 subprograms that require
	overriding if we are not in Ada 2022 mode; warn on other
	references to Ada 2022 entities when not in Ada 2022 mode.
	* sem_ch13.adb (Inherit_Aspects_At_Freeze_Point): Inherit
	Ada_2020_Only.
	* libgnat/a-cdlili.ads (Empty): Adding pragma Ada_2022.
	* libgnat/a-cidlli.ads (Empty): Adding pragma Ada_2022.
	* libgnat/a-ciorma.ads (Empty): Adding pragma Ada_2022.
	* libgnat/a-cobove.ads (Empty): Adding pragma Ada_2022.
	* libgnat/a-coorma.ads (Empty): Adding pragma Ada_2022.
	(New_Vector): Adding pragma Ada_2022.
	(Insert_Vector): Adding pragma Ada_2022.
	(Prepend_Vector): Adding pragma Ada_2022.
	(Append_Vector): Adding pragma Ada_2022.