Merge from gcc top-level.

Merge from gcc top-level.

./:
	* configure.ac: Add target-libgo to target_libraries.  Set
	and substitute GOC_FOR_BUILD and GOC_FOR_TARGET.
	* Makefile.tpl (BUILD_EXPORTS): Add GOC and GOCFLAGS.
	(HOST_EXPORTS): Add GOC.
	(BASE_TARGET_EXPORTS): Add GOC.
	(GOC_FOR_BUILD, GOCFLAGS, GOC_FOR_TARGET): New variables.
	(GOCFLAGS_FOR_TARGET): New variable.
	(EXTRA_HOST_FLAGS): Add GOC.
	(EXTRA_TARGET_FLAGS): Add GOC and GOCFLAGS.
	* Makefile.def (target_modules): Add libgo.
	(flags_to_pass): Add GOC_FOR_TARGET and GOCFLAGS_FOR_TARGET.
	(dependencies): Add dependency from configure-target-libgo to
	configure-target-libffi and all-target-libstdc++-v3.  Add
	dependencies from all-target-libgo to all-target-libffi.
	(languages): Add go.
	* configure: Rebuild.
	* Makefile.in: Rebuild.

	* config-ml.in: Add Go support: treat GOC and GOCFLAGS like other
	compiler/flag environment variables.

	* configure.ac: Check for lang_requires_boot_languages in
	config-lang.in files.
	* configure: Rebuild.

	PR fortran/32049
	* Makefile.def: Add libquadmath; build it with language=fortran.
	* configure.ac: Add libquadmath.
	* Makefile.tpl: Handle multiple libs in check-[+language+].
	* Makefile.in: Regenerate.
	* configure: Regenerate.

	* configure.ac: Fix spelling in option names.
	* configure: Regenerated.

	PR bootstrap/39622
	* configure.ac (FLAGS_FOR_TARGET): Add include-fixed path.
	* configure: Regenerated.

	* config/cloog.m4: Add -enable-cloog-backend=(isl|ppl|ppl-legacy) to
	define the cloog backend to use. Furthermore, only pass the ppllibs to
	the configure checks, if necessary.
	* configure: Regenerate.

	* config/cloog.m4: Use CLooG predefined macro to check for CLooG PPL.
	* configure: regenerate

	* config/cloog.m4: Fix typo.  verison -> version.
	* configure: Regenerate.

	* config/cloog.m4: Pass ppl libraries to the CLooG version check.
	* configure: Regenerate.

	* configure.ac: Support official CLooG.org versions.
	* configure: Regenerate.
	* config/cloog.m4: New.

	* configure.ac (*-*-darwin*): Use mh-darwin for all Darwin variants.
	* configure: Regenerate.

config/:
	* cloog.m4 (CLOOG_INIT_FLAGS): Fix spelling in option names.

	* bootstrap-lto: Use -flto.

	* mh-darwin: Renamed from mh-ppc-darwin.