Review Request JDK-8218461: test/jdk/java/lang/invoke/VarHandles should be generated rather than manually edited

[Mandy Chung]

This patch fixes up X-VarHandleTest* template files that are
used to generate VarHandles tests.  Since VarHandle::equals
and VarHandle::hashCode methods are no longer implemented [1],
I rename the testEqualsAndHashCode method to testEquals
and further clean up the test case.

Webrev:
    http://cr.openjdk.java.net/~mchung/jdk13/webrevs/8218461/webrev.00/

Thanks
Mandy
[1] https://bugs.openjdk.java.net/browse/JDK-8215648