JNI VERSION CHANGE: RFR: 8145098: JNI GetVersion should return JNI_VERSION_9

[Rachel Protacio]

Hello!

Small but important change for review: updating the JNI_VERSION and in 
so doing, changing the format from JNI_VERSION_1_x to JNI_VERSION_x_y 
(see code/bug for details).

Bug: https://bugs.openjdk.java.net/browse/JDK-8145098

hotspot repo webrev: http://cr.openjdk.java.net/~rprotacio/JNI_hotspot/
jdk repo webrev: http://cr.openjdk.java.net/~rprotacio/JNI_jdk/

I grep'ed through the code to find references to the current JNI version 
and believe I have caught all the ones that needed changing, plus the 
fact that all these tests pass:

  * local hotspot jtreg tests
  * my own sample JNI test to print and visually inspect the version
    (essentially what is performed by the updated
    hotspot/test/native_sanity/JniVersion.java test)
  * jck vm tests
  * local rbt colcated and noncolocated tests, especially for the
    purpose of hitting tonga/src/nsk/share/jvmti tests where
    JNI_GetVersion() is used

Thank you,
Rachel