[Ada] New parameter Quiet for procedure GNAT.Command_Line.Getopt

[Ada] New parameter Quiet for procedure GNAT.Command_Line.Getopt

Getopt procedure is parsing the command line or set of strings. If the
command line contains unknown switch than the Getopt prints error
message to the console and raises the exception Invalid_Switch. The
printing can be inappropriate in some cases. The new parameter Quiet
allows avoiding console output.

2019-08-12  Dmitriy Anisimkov  <anisimko@adacore.com>

gcc/ada/

	* libgnat/g-comlin.ads, libgnat/g-comlin.adb (Getopt): Add
	parameter Quiet. Need to do not output error messages to
	console. Invalid_Switch exception generation surrounded by an
	error message.

From-SVN: r274307