alias.c (get_alias_set): Use the element alias-set for arrays.

2008-06-11  Richard Guenther  <rguenther@suse.de>

	* alias.c (get_alias_set): Use the element alias-set for arrays.
	(record_component_aliases): For arrays and vectors do nothing.
	* c-common.c (strict_aliasing_warning): Handle the cases
	of alias set zero explicitly.
	* Makefile.in (dfp.o-warn): Add -Wno-error.

From-SVN: r136679