Reorganize the analysis of basic block predication.

Reorganize the analysis of basic block predication.

2010-05-26  Sebastian Pop  <sebastian.pop@amd.com>

	* tree-if-conv.c (add_to_dst_predicate_list): Do not pass a statemet
	iterator in parameter.  Do not generate code during the analysis.
	(tree_if_convert_cond_stmt): Removed.
	(tree_if_convert_stmt): Removed.
	(predicate_bbs): New.
	(if_convertible_loop_p): Call predicate_bbs.
	(tree_if_conversion): Simplify the top-level logic as predicate_bbs
	now contains all the analysis part.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@159886 138bc75d-0d04-0410-961f-82ee72b054a4