configure.ac: Add ACX_NONCANONICAL_HOST.

gnattools/
	* configure.ac: Add ACX_NONCANONICAL_HOST.
	* configure: Regenerate.
	* Makefile.in: Replace host_alias with host_noncanonical.
	(gnattools-cross): Do not rename the tools.
gcc/
	* configure.ac: Add ACX_NONCANONICAL_HOST.
	* configure: Regenerate.
	* Makefile.in: Set host_noncanonical.
gcc/ada
	* gcc-interface/Make-lang.in (GNATMAKE_FOR_HOST): In the canadian
	cross case, use host_noncanonical instead of host as prefix.
	(GNATBIND_FOR_HOST): Likewise.
	(GNATLINK_FOR_HOST): Likewise.
	(GNATLS_FOR_HOST): Likewise.

From-SVN: r236267