PR modula2/109336 pass -fmod= though and build m2/stage2/cc1gm2 libs

This patch enables gm2 to pass -fmod= though to cc1gm2.  It also
builds the libraries for m2/stage2/cc1gm2 with no named path and
full debugging.

gcc/m2/ChangeLog:

	PR modula2/109336
	* Make-lang.in (GM2_O): Set to -O0.
	(GM2_LIBS): Remove target libraries and replace with build libs.
	(BUILD-LIBS): New declaration.
	(m2/gm2-libs/libgm2.a): New rule.
	(m2/gm2-libs/%.o): New rule.
	(m2/gm2-libs/choosetemp.o): New rule.
	* gm2-compiler/M2ColorString.mod (append): Use ADR rather than
	implicit conversion.
	* gm2-compiler/M2Comp.mod (Compile): Add qprintf messages for when
	a source file is not found.  Improve comments and formatting.
	* gm2-libs-ch/cgetopt.c (cgetopt_cgetopt_long): Remove
	ansi-decl.h.  Add getopt.h.
	(cgetopt_cgetopt_long_only): Change cgetopt_ to getopt_.
	* gm2spec.cc (lang_specific_driver): Do not skip -fmod=.
	Remove comment.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>