RFR[T]: 8233495: Some fieldDescriptor methods can pass existing constantPoolHandle

[Claes Redestad]

Hi,

(trivial?) patch to avoid dereferencing and then subsequent implicit re-
handleificiation of a constantPoolHandle in two places in
fieldDescriptor.inline.hpp. This has a minor impact on field resolution
overhead in various places.

Bug:    https://bugs.openjdk.java.net/browse/JDK-8233495
Webrev: http://cr.openjdk.java.net/~redestad/8233495/open.00/

Testing: tier1

Thanks!

/Claes