message: Fix unused variable warning in opt build
  TESTED with existing tests
diff: @@ -202,6 +202,7 @@ inline APFloat convertFloatToType(FloatType ft, APFloat value) {
  bool losesInfo;
  auto status = value.convert(ft.getFloatSemantics(),
  APFloat::rmNearestTiesToEven, &losesInfo);
  + (void)status; // unused in opt mode
  assert((status & (APFloat::opDivByZero | APFloat::opInvalidOp)) == 0 &&
  "could not convert to float const");
  return value;
  