Update top level config files with copies from the official repository.

	2020-01-01  Ben Elliston  <bje@gnu.org>

	* config.guess: Update copyright years.
	* config.sub: Likewise.

	2019-12-21  Ben Elliston  <bje@gnu.org>

	* config.guess (set_cc_for_build): Prevent multiple calls by
	checking if $tmp is already set. We can't check CC_FOR_BUILD as
	the user may set it externally. Thanks to Torbj?rn Granlund for
	the bug report.

	2019-12-21  Torbj?rn Granlund  <tg@gmplib.org>

	* config.guess (alpha:Linux:*:*): Guard against missing
	/proc/cpuinfo by redirecting standard error to /dev/null.

	2019-09-12  Daniel Bittman  <danielbittman1@gmail.com>

	* config.guess (*:Twizzler:*:*): New.
	* config.sub (-twizzler*): New.

	2019-07-24  Ben Elliston  <bje@gnu.org>

	* config.guess (mips:OSF1:*.*): Whitespace cleanup.

	2019-06-30  Ben Elliston  <bje@gnu.org>

	* config.sub (case $os): Match nsk* and powerunix. Don't later
	match nsk* and set os=nsk which removes the OS version number.

	2019-06-30  Ben Elliston  <bje@gnu.org>

	* config.sub: Recognise os108*.

	2019-06-26  Ben Elliston  <bje@gnu.org>

	* config.sub (hp300): Set $os to hpux.

	2019-06-26  Ben Elliston  <bje@gnu.org>

	* config.sub (vsta): Move into alphabetical order.

	2019-06-10  Ben Elliston  <bje@gnu.org>

	* config.guess (*:OS108:*:*): Recognise new OS.

	2019-05-28  Ben Elliston  <bje@gnu.org>

	* config.guess (*:Darwin:*:*): Run xcode-select to determine if a
	system compiler is installed. If not, do not run set_cc_for_build,
	as the default cc will open a dialog box asking to install
	Xcode. If no C compiler is available, guess based on uname -p and
	uname -m.

	2019-05-28  Ben Elliston  <bje@gnu.org>

	* config.guess (*:Darwin:*:*): Simplify UNAME_PROCESSOR.