[9] RFR (M): 8035828: Turn on @Stable support in VM

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8035828/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8035828

@Stable was added in 8 (back in September, 2013) as an experimental 
feature. Future JSR292 performance improvements rely on it, so it should 
be turned on by default.

Also, as part of this change, I integrate unit tests on @Stable. They 
were part of initial implementation [1], but were broken when the 
annotation was moved to java.lang.invoke and made package-private. It 
blocked their integration. Now they are fixed.

Thanks!

Best regards,
Vladimir Ivanov

[1] http://cr.openjdk.java.net/~vlivanov/8001107/webrev.04/