[Ada] Improve performance for case-insensitive regular expressions

gcc/ada/

	* libgnat/s-regpat.adb (Match): Handle the case where Self.First
	is not NUL (so we know the first character we are looking for),
	but case-insensitive matching has
	been specified.
	(Optimize): In the case of an EXACTF Op, set Self.First as is
	done in the EXACT case, except with the addition of a call to
	Lower_Case.
1 file changed