PR tree-optimization/53226
	* tree-ssa-forwprop.c (ssa_forward_propagate_and_combine): Remove
	prev and prev_initialized vars, gimple_set_plf (stmt, GF_PLF_1, false)
	before processing it and gimple_set_plf (stmt, GF_PLF_1, true) if it
	doesn't need to be revisited, look for earliest stmt with
	!gimple_plf (stmt, GF_PLF_1) if something changed.

	* gcc.c-torture/compile/pr53226.c: New test.

From-SVN: r187328