RFR (XS) JDK-8024804: Crash when InterfaceMethodref resolves to Object.registerNatives

[Lois Foltan]

Please review the following fix:

Webrev:
     http://javaweb.us.oracle.com/~lfoltan/webrev/bug_jdk8024804/

Bug: Crash when InterfaceMethodref resolves to Object.registerNatives
     https://bugs.openjdk.java.net/browse/JDK-8024804

Summary of fix:
     When trying to look up the registerNatives() method within Object's 
super() class, a crash occurred
     due to the fact that an Object's superclass is NULL.  Added a check 
for a NULL superclass prior to
     continuation of method look up.

Tests:
     JTREG, vm.quick.testlist
     test/runtime/8024804/RegisterNatives.java added

Thank you, Lois