* gimple-ssa-sprintf.c: Include domwalk.h.
	(class sprintf_dom_walker): New class, derived from dom_walker.
	(sprintf_dom_walker::before_dom_children): New function.
	(struct call_info): Moved into sprintf_dom_walker class
	(compute_formath_length, handle_gimple_call): Likewise.
	(sprintf_length::execute): Call the dominator walker rather
	than walking the statements.

From-SVN: r254156