RFR (XS) 8175269: [s390] cleanup calls to vtable_start_offset() and vtable_length_offset()

[Schmidt, Lutz]

Hi all,

May I kindly request reviews for my very small cleanup change? Further down the road, I would need a sponsor, too.

Bug: https://bugs.openjdk.java.net/browse/JDK-8175269
Webrev: http://cr.openjdk.java.net/~lucy/webrevs/8175269/

Description:
The two static functions are declared/defined in class Klass, but accessed via the subclass InstanceKlass. This is true for s390 only. All other architectures access them via the defining class. My change removes the “detour” via InstanceKlass.

Thanks,
Lutz