Merge modula-2 front end onto gcc.

This commit merges the devel/modula2 into master.
The libraries reside in libgm2, the compiler in gcc/m2
and the testsuite in gcc/testsuite/gm2.

	* configure.ac (target_libraries): Add target-libgm2.
	Add NCN_STRICT_CHECK_TARGET_TOOLS entry for gm2.
	Add GCC_TARGET_TOOL entry for gm2.  (compare_exclusions)
	add gcc/m2/gm2-compiler/M2Version,
	gcc/m2/gm2-compiler-boot/SYSTEM and gcc/m2/gm2version.
	* Makefile.def (target_modules): Add libgm2.  (flags_to_pass)
	Add GM2_FOR_TARGET, GM2FLAGS_FOR_TARGET.  (dependencies) Add
	all-target-libgm2 and on=all-target-libatomic.  (languages)
	Add entry for language=m2 with gcc-check-target=check-m2
	and lib-check-target=check-target-libgm2.
	* Makefile.tpl (BUILD_EXPORTS): Add definition for GM2
	and GM2FLAGS.  (HOST_EXPORTS) Add definition for GM2.
	(BASE_TARGET_EXPORTS) Add definition for GM2.
	(GM2_FOR_BUILD) Defined.  (GM2FLAGS) Defined.
	(GM2_FOR_TARGET) Defined.  (GM2FLAGS_FOR_TARGET) Defined.
	(EXTRA_HOST_FLAGS) Defined.  (POSTSTAGE1_FLAGS_TO_PASS)
	Add GM2 and GM2_FOR_BUILD.  (EXTRA_TARGET_FLAGS) Add
	GM2 and GM2FLAGS.  (EXTRA_GCC_FLAGS) Add GM2_FOR_TARGET.

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

configure.ac

@@ -141,7 +141,7 @@ host_libs="intl libiberty opcodes bfd readline tcl tk itcl libgui zlib libbacktr
 # binutils, gas and ld appear in that order because it makes sense to run
 # "make check" in that particular order.
 # If --enable-gold is used, "gold" may replace "ld".
-host_tools="texinfo flex bison binutils gas ld fixincludes gcc cgen sid sim gdb gdbserver gprof etc expect dejagnu m4 utils guile fastjar gnattools libcc1 gotools c++tools"
+host_tools="texinfo flex bison binutils gas ld fixincludes gcc cgen sid sim gdb gdbserver gprof etc expect dejagnu m4 utils guile fastjar gnattools libcc1 gm2tools gotools c++tools"
 
 # these libraries are built for the target environment, and are built after
 # the host libraries and the host tools (which may be a cross compiler)
@@ -162,6 +162,7 @@ target_libraries="target-libgcc \
 		target-libffi \
 		target-libobjc \
 		target-libada \
+		target-libgm2 \
 		target-libgo \
 		target-libphobos \
 		target-zlib"
@@ -500,6 +501,14 @@ if test "${ENABLE_LIBADA}" != "yes" ; then
   noconfigdirs="$noconfigdirs gnattools"
 fi
 
+AC_ARG_ENABLE(libgm2,
+[AS_HELP_STRING([--enable-libgm2], [build libgm2 directory])],
+ENABLE_LIBGM2=$enableval,
+ENABLE_LIBGM2=no)
+if test "${ENABLE_LIBGM2}" != "yes" ; then
+  noconfigdirs="$noconfigdirs gm2tools"
+fi
+
 AC_ARG_ENABLE(libssp,
 [AS_HELP_STRING([--enable-libssp], [build libssp directory])],
 ENABLE_LIBSSP=$enableval,
@@ -3746,6 +3755,7 @@ NCN_STRICT_CHECK_TARGET_TOOLS(GCC_FOR_TARGET, gcc, ${CC_FOR_TARGET})
 NCN_STRICT_CHECK_TARGET_TOOLS(GFORTRAN_FOR_TARGET, gfortran)
 NCN_STRICT_CHECK_TARGET_TOOLS(GOC_FOR_TARGET, gccgo)
 NCN_STRICT_CHECK_TARGET_TOOLS(GDC_FOR_TARGET, gdc)
+NCN_STRICT_CHECK_TARGET_TOOLS(GM2_FOR_TARGET, gm2)
 
 ACX_CHECK_INSTALLED_TARGET_TOOL(AR_FOR_TARGET, ar)
 ACX_CHECK_INSTALLED_TARGET_TOOL(AS_FOR_TARGET, as)
@@ -3784,6 +3794,8 @@ GCC_TARGET_TOOL(gccgo, GOC_FOR_TARGET, GOC,
 		[gcc/gccgo -B$$r/$(HOST_SUBDIR)/gcc/], go)
 GCC_TARGET_TOOL(gdc, GDC_FOR_TARGET, GDC,
 		[gcc/gdc -B$$r/$(HOST_SUBDIR)/gcc/], d)
+GCC_TARGET_TOOL(gm2, GM2_FOR_TARGET, GM2,
+		[gcc/gm2 -B$$r/$(HOST_SUBDIR)/gcc/], m2)
 GCC_TARGET_TOOL(ld, LD_FOR_TARGET, LD, [ld/ld-new])
 GCC_TARGET_TOOL(lipo, LIPO_FOR_TARGET, LIPO)
 GCC_TARGET_TOOL(nm, NM_FOR_TARGET, NM, [binutils/nm-new])
@@ -3910,6 +3922,9 @@ AC_SUBST(stage2_werror_flag)
 # Specify what files to not compare during bootstrap.
 
 compare_exclusions="gcc/cc*-checksum\$(objext) | gcc/ada/*tools/*"
+compare_exclusions="$compare_exclusions | gcc/m2/gm2-compiler-boot/M2Version*"
+compare_exclusions="$compare_exclusions | gcc/m2/gm2-compiler-boot/SYSTEM*"
+compare_exclusions="$compare_exclusions | gcc/m2/gm2version*"
 case "$target" in
   hppa*64*-*-hpux*) ;;
   hppa*-*-hpux*) compare_exclusions="$compare_exclusions | */libgcc/lib2funcs* | gcc/function-tests.o" ;;