6889300: assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes")
Summary: PhiNode::Ideal() should return TOP for Phi node with no users.
Reviewed-by: never, jrose
6889656: assert(lo_lrg->lo_degree() || !lo_no_simplify,"Live range was lo-degree before coalesce
Summary: Restore the original code: uint i = _hi_degree.
Reviewed-by: never, jrose