Use -fopt-info in unswitch pass.

Use -fopt-info in unswitch pass.

gcc/ChangeLog:

	* profile-count.c (profile_count::dump): Add function
	that can dump to a provided buffer.
	(profile_probability::dump): Likewise.
	* profile-count.h: Likewise.
	* tree-ssa-loop-unswitch.c (tree_unswitch_single_loop):
	Use dump_printf_loc infrastructure.
	(tree_unswitch_outer_loop): Likewise.
	(find_loop_guard): Likewise.
	(hoist_guard): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.dg/loop-unswitch-1.c: Adjust test-case based on
	dump_printf_loc.
	* gcc.dg/loop-unswitch-2.c: Likewise.
	* gcc.dg/loop-unswitch-3.c: Likewise.
	* gcc.dg/loop-unswitch-4.c: Likewise.
	* gcc.dg/loop-unswitch-5.c: Likewise.