[Ada] Accept aspect Relaxed_Initialization on generic subprograms

[Ada] Accept aspect Relaxed_Initialization on generic subprograms

gcc/ada/

	* sem_attr.adb (Analyze_Attribute): Correct prefix of 'Result
	this prefix is a generic function but the enclosing aspect or
	pragma is attached to its instance.
	* sem_ch12.adb (Analyze_Generic_Subprogram_Declaration): Analyze
	generic subprogram formal parameters (including the implicit
	result of a generic function) and only then analyse its aspects,
	because with Relaxed_Initialization the aspect expression might
	refer to those formal parameters.
	* sem_ch13.adb (Analyze_Aspect_Relaxed_Initialization): Accept
	aspect on generic subprograms; install formal parameters of a
	generic subprogram but not formal parameters of the generic unit
	itself (the previous code was inspired by aspects Post and
	Depends, where both kinds of formals are allowed).
	* sem_util.ads (Enter_Name): Fix name of a subprogram referenced
	in comment.