[LWorld] Value type array support for C2 (and lots of bug fixes)

[Roland Westrelin]

> http://cr.openjdk.java.net/~thartmann/valhalla/lworld_arrays/webrev.01/

I was thinking:

} else if (phi->bottom_type()->isa_valuetype() && !value->is_ValueType()) {
  assert(value->bottom_type()->remove_speculative() == TypePtr::NULL_PTR, "Anything other than null?");
  inc_sp(1);
  uncommon_trap(Deoptimization::Reason_null_check, Deoptimization::Action_none);

Roland.