RFR (trivial) 8199137: StringInternSync test crashes in exit verification

[coleen.phillimore at oracle.com]

Summary: java_lang_String::equals(oop, oop) was buggy.

open webrev at http://cr.openjdk.java.net/~coleenp/8199137.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8199137

This verification is rarely called, but was called for one of the 
internal tests, which produced this crash.  I think Erik Osterlund found 
this bug at one point too.

Thanks,
Coleen