flow.c: Move all basic block reordering code into its own file.

flow.c: Move all basic block reordering code into its own file.

	* flow.c: Move all basic block reordering code into its own file.
	(create_basic_block): Externalize.
	* bb-reorder.c: New file. Copy all basic block reordering code from
	flow.c to this file.
	(reorder_basic_blocks): Fix fencepost error in for-loop.
	(reorder_basic_blocks): Remove braces from single statement for-loops.
	* basic-block.h: Add declaration for create_basic_block.
	* Makefile.in: Add rules for bb-reorder.o.

From-SVN: r32585