Reimplement rewrite_virtuals_into_loop_closed_ssa

Reimplement rewrite_virtuals_into_loop_closed_ssa

2015-08-31  Tom de Vries  <tom@codesourcery.com>

	* tree-ssa-loop-manip.c (find_uses_to_rename_stmt)
	(find_uses_to_rename_bb, find_uses_to_rename): Add and handle use_flags
	parameter.
	(find_uses_to_rename_def, find_uses_to_rename_in_loop): New function.
	(rewrite_into_loop_closed_ssa_1): New function, factored out of ...
	(rewrite_into_loop_closed_ssa): ... here.
	(replace_uses_in_dominated_bbs): Remove function.
	(rewrite_virtuals_into_loop_closed_ssa): Reimplement using
	rewrite_into_loop_closed_ssa_1.

From-SVN: r227342