RFR: 8182997: [MVT] ValueTypeArray.java fails with "assert(false) failed: unexpected TypeAryPtr::_klass"

[Roland Westrelin]

Thanks for the review.

> Okay, that's unfortunate. I'm fine with the changes but maybe you
> could guard the symbol scanning code by ValueArrayFlatten or
> EnableValhalla/EnableMVT.

I don't think flattened arrays make a difference here. We could also
assert for EnableValhalla || EnableMVT if the logic find a [Q array
declaration. Or do you think that logic must be skipped if
!EnableValhalla && !EnableMVT?

Roland.