[Ada] Fix Compile_Time_(Error|Warning) as non-configuration pragmas

[Ada] Fix Compile_Time_(Error|Warning) as non-configuration pragmas

Uses of Compile_Time_Error and Compile_Time_Warning as configuration
pragmas were detected with a custom check in semantic analysis. Now they
are detected with an existing general check in parser.

gcc/ada/

	* sem_prag.adb (Analyze_Pragma): Remove custom check for
	Compile_Time_Error and Compile_Time_Warning pragmas.
	* snames.ads-tmpl (Compile_Time_Error, Compile_Time_Warning):
	Move beyond Last_Configuration_Pragma_Name.