message: add new rval, pull deref early
diff: @@ -503,6 +503,11 @@ fn codegen_stmt<'tcx>(
  let val = codegen_operand(fx, operand);
  lval.write_cvalue(fx, val);
  }
  + Rvalue::CopyForDeref(place) => {
  + let cplace = codegen_place(fx, place);
  + let val = cplace.to_cvalue(fx);
  + lval.write_cvalue(fx, val)
  + }
  Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => {
  let place = codegen_place(fx, place);
  let ref_ = place.place_ref(fx, lval.layout());
  