Fix a problematic logic at unswitch-loops pass.

2010-04-07  Jing Yu  <jingyu@google.com>
            Zdenek Dvorak  <ook@ucw.cz>

	PR tree-optimization/42720
	* tree-ssa-loop-unswitch.c (tree_ssa_unswitch_loops): Move one-time
	loop unswitch conditions here from
	(tree_unswitch_single_loop).

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158138 138bc75d-0d04-0410-961f-82ee72b054a4