[9] Review Request: 8058858 JRE 8u20 crashes while using Japanese IM on Windows

[Sergey Bylokhov]

Hello.
Please review the fix for jdk 9. The problem is that we call 
DeleteLocalRef() on the cached global reference returned by 
JNU_ClassString(env).

Bug: https://bugs.openjdk.java.net/browse/JDK-8058858
Webrev can be found at: http://cr.openjdk.java.net/~serb/8058858/webrev.00

--
Best regards, Sergey.