RFR 8202171: Some oopDesc functions compare this with NULL

[Harold David Seigel]

Hi,

Please review this JDK-12 fix for bug JDK-8202171.  The fix changes a 
few functions in oop.cpp into static functions to avoid comparisons 
between 'this' and NULL.

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8202171/webrev/index.html

JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8202171

This fix was regression tested by running Mach5 tiers 1 and 2 tests and 
builds on Linux-X64, Windows, Solaris Sparc, and Mac OS X, running tiers 
3-5 tests on Linux-x64, and by running JCK-11 Lang and VM tests on 
Linux-x64.

Thanks, Harold