Rename configure.in to configure.ac

[Alan Modra]

More modernisation.

bfd/
	* configure.ac: Rename from configure.in.
	* Makefile.in: Regenerate.
	* config.in: Regenerate.
	* doc/Makefile.in: Regenerate.
opcodes/
	* configure.ac: Rename from configure.in.
	* Makefile.in: Regenerate.
	* config.in: Regenerate.
binutils/
	* configure.ac: Rename from configure.in.
	* Makefile.in: Regenerate.
	* config.in: Regenerate.
	* doc/Makefile.in: Regenerate.
gas/
	* configure.ac: Rename from configure.in.
	* Makefile.in: Regenerate.
	* config.in: Regenerate.
	* doc/Makefile.in: Regenerate.
gprof/
	* configure.ac: Rename from configure.in.
	* configure.ac: Rename from configure.in.
	* Makefile.in: Regenerate.
	* gconfig.in: Regenerate.
ld/
	* configure.ac: Rename from configure.in.
	* Makefile.in: Regenerate.
	* config.in: Regenerate.

-- 
Alan Modra
Australia Development Lab, IBM