tree-scalar-evolution.c: New file.

	* tree-scalar-evolution.c: New file.
	* tree-scalar-evolution.h: New file.
	* tree-ssa-loop-niter.c: New file.
	* Makefile.in (SCEV_H): New.
	(tree-scalar-evolution.o, tree-ssa-loop-niter.o): Add new files.
	* cfgloop.h (struct loop): Add bounds field.
	* tree-flow.h (struct tree_niter_desc): New type.
	(number_of_iterations_cond, number_of_iterations_exit,
	loop_niter_by_eval, find_loop_niter_by_eval,
	estimate_numbers_of_iterations, can_count_iv_in_wider_type,
	free_numbers_of_iterations_estimates): Declare.
	* tree.h (lower_bound_in_type, upper_bound_in_type): Declare.
	* params.def (PARAM_MAX_ITERATIONS_TO_TRACK): New parameter.
	* doc/invoke.texi (max-iterations-to-track): Document.

From-SVN: r84340