RFR: 8154765: [JVMCI] Support dimensional granularity for stable array fields

[Andreas Woess]

Please review:
http://cr.openjdk.java.net/~aw/8154765/webrev/
https://bugs.openjdk.java.net/browse/JDK-8154765

This change adds an optional stableDimensions parameter to 
ConstantReflectionProvider.readStableFieldValue that allows the number 
of stable array dimensions to be specified more fine-granular than 
inferring it from the type of the field.

Thanks,
Andreas