RFR(S): 8143245: Zero build requires disabled warnings

[Severin Gehwolf]

Hi,

Could somebody please review and sponsor this Zero-only change. The
hotspot build for Zero had some compiler warnings disabled for no good
reason. I've fixed the code so the silencing isn't necessary any more.

Bug: https://bugs.openjdk.java.net/browse/JDK-8143245
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8143245/webrev.01/

Thoughts?

Thanks,
Severin