* Makefile.in, configure.in, config.host, mkheaders.in: Replace
	uses of ${target_alias} for directory names (and other places which
	won't like the empty string) with ${target_noncanonical}.  Introduce
	call early in configure.in to _GCC_TOPLEV_NONCANONICAL_TARGET so it's
	available.
	* configure: Regenerate.

From-SVN: r72457