par-prag.adb (Pragma_Warnings): Update for extended form of pragma Warnings.

par-prag.adb (Pragma_Warnings): Update for extended form of pragma Warnings.

2015-02-05  Yannick Moy  <moy@adacore.com>

	* par-prag.adb (Pragma_Warnings): Update for extended form
	of pragma Warnings. The "one" argument case may now have 2 or
	3 arguments.
	* sem_prag.adb (Analyze_Pragma/Pragma_Warnings): Update for
	extended form of pragma Warnings. Pragma with tool name is either
	rewritten as null or as an equivalent form without tool name,
	before reanalysis.
	* snames.ads-tmpl (Name_Gnatprove): New name.

From-SVN: r220447