[Ada] Implement AI12-0291 (Jorvik profile)

[Ada] Implement AI12-0291 (Jorvik profile)

2020-06-08  Steve Baird  <baird@adacore.com>

gcc/ada/

	* libgnat/s-rident.ads: Add Jorvik to the Profile_Name
	enumeration type.  Add an element for Jorvik to the array
	aggregate that is the initial value of the constant
	Profile_Info.
	* targparm.adb (Get_Target_Parameters): Handle "pragma Profile
	(Jorvik);" similarly to "pragma Profile (Ravenscar);".
	* snames.ads-tmpl: Declare Name_Jorvik Name_Id. Unlike
	Ravenscar, Jorvik is not a pragma name and has no corresponding
	element in the Pragma_Id enumeration type; this means that its
	declaration must not occur between those of First_Pragma_Name
	and Last_Pragma_Name.
	* sem_prag.adb (Analyze_Pragma): Add call to
	Set_Ravenscar_Profile for Jorvik, similar to the existing calls
	for Ravenscar and the GNAT Ravenscar variants.