RFR 8183133: [MVT] Arraylength method handle on Q-typed array shouldn't use ArrayAccessor.lengthL(Object[])

[Maurizio Cimadamore]

Hi,
This patch adds an arrayLength() method handle to ValueType. This is 
necessary, as the standard arraylength generation strategy performed in 
MethodHandles doesn't work on value-typed arrays.

http://cr.openjdk.java.net/~mcimadamore/8183133/

Thanks
Maurizio