RFR [9] 8041972: Add improved parse/format methods for Long/Integer

[Claes Redestad]

Hi,

please review this patch to add offset based variants of 
Integer.parseInt/parseUnsignedInt, Long.parseLong/parseUnsignedLong and 
expose them through JavaLangAccess along with formatUnsignedInt/-Long. 
This is proposed to enable a number of minor optimizations, starting 
with https://bugs.openjdk.java.net/browse/JDK-8006627

Webrev: http://cr.openjdk.java.net/~redestad/8041972/webrev.0/

Thanks!

/Claes