RFR(M): 8223029: [lworld] C2 support for widening/narrowing conversion "[QFoo;" <: "[LFoo;”

[Roland Westrelin]

> This happens when we access a [MyValue? array. Similar to accessing an Object array, we cannot
> statically determine if the array is flattened and need to emit a runtime check. But at least we
> know the exact type and can avoid the runtime call.

Thanks. That makes sense. Change looks good then.

Roland.