* config.gcc: Where xm-host.h used to include another
	xm-host.h, list the nested header directly in xm_file.  Remove
	references to deleted files.  Can now use sparc/xm-sp64.h for
	sparcv9-*-solaris*.

	* config/xm-linux.h, config/arm/xm-linux.h,
	config/i386/xm-dos.h, config/i386/xm-gnu.h,
	config/i386/xm-linux.h, config/i386/xm-openbsd.h,
	config/i860/xm-fx2800.h, config/m68k/xm-atari.h,
	config/m68k/xm-linux.h, config/m68k/xm-sun3.h,
	config/sparc/xm-linux.h, config/sparc/xm-sysv4-64.h:
	Delete.

	* config/alpha/xm-alpha-interix.h: Don't include alpha/xm-alpha.h.
	* config/mips/xm-iris5.h: Don't include mips/xm-mips.h.  Don't
	bother to wrap #undef in #ifdef.
	* config/pa/xm-linux.h, config/rs6000/xm-sysv4.h:
	Don't include xm-linux.h.
	* config/sparc/xm-sp64.h: Don't include sparc/xm-sparc.h.

	* configure.in: Wrap regexps using [] in changequote block.
	Use expr : not echo | grep.  Simplify regexps.
	* configure: Regenerate.

	56 xm-files remain, 22 xm-arch.

From-SVN: r40392