Introduce target independent copies of document chapters.

Introduce target independent copies of document chapters.

This patch introduces target independent copies of document chapters
which will be used if HAVE_PYTHON is no, thus providing a fall back
for documentation production.

gcc/m2/ChangeLog:

	* doc/gm2.texi: Tidy up mailing testsuite results
	(formatting).
	* Make-lang.in (gm2-libs-texi-check): Copy
	target-dependent copy
	if HAVE_PYTHON is no.  (gm2-libs-rst-check) Copy
	target-dependent copy
	if HAVE_PYTHON is no.  (SYSTEM-pim-texi-check) Copy
	target-dependent copy
	if HAVE_PYTHON is no.  (SYSTEM-pim-rst-check) Copy
	target-dependent copy
	if HAVE_PYTHON is no.  (SYSTEM-iso-texi-check) Copy
	target-dependent copy
	if HAVE_PYTHON is no.  (SYSTEM-iso-rst-check) Copy
	target-dependent copy
	if HAVE_PYTHON is no.  (Builtins.texi-check) Copy
	target-dependent copy if HAVE_PYTHON is no.
	(Builtins.rst-check) Copy target-dependent copy if
	HAVE_PYTHON is no.
	* Make-maintainer.in (m2-target-independent-doc): New rule.
	(m2-target-independent-doc-texi) New rule.
	(m2-target-independent-doc-rst) New rule.
	* gm2-libs-coroutines/SYSTEM.def: Tidied up comments.
	* gm2-libs-iso/README.texi: Corrected dates.
	* gm2-libs-iso/SYSTEM.def: Tidied up comments.
	* gm2-libs/README.texi: Corrected dates.
	* tools-src/def2doc.py (emit_texinfo_content): Do not change state
	in texinfo files.  Replace @SYSTEM_DATATYPES@ with 'Target
	specific data types.'.  Replace @SYSTEM_TYPES@ with '(* Target
	specific data types.  *)'
	* target-independent/Builtins.rst: New file.
	* target-independent/Builtins.texi: New file.
	* target-independent/gm2-libs.rst: New file.
	* target-independent/gm2-libs.texi: New file.
	* target-independent/readme.txt: New file.
	* target-independent/SYSTEM-iso.rst: New file.
	* target-independent/SYSTEM-iso.texi: New file.
	* target-independent/SYSTEM-pim.rst: New file.
	* target-independent/SYSTEM-pim.texi: New file.

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