RFR: 8276658: Clean up JNI local handles code

[Coleen Phillimore]

On Wed, 10 Nov 2021 17:16:29 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> JNI Local handles can only be created by JavaThread (there's an assert in make_local) but the fields are added to Thread.
> Move the fields to JavaThread and adding JavaThread* argument.
> Also, the global freelist isn't very useful now that global JNI handles don't use JNIHandleBlock, so the locking that claims incorrectly to block for safepoint is removed.
> Lastly, there's at least 3 places that duplicate pushing a new JNIHandleBlock to the thread for temporarily adding JNI local handles. These have been moved to common code with a JNIHandleMark object, moved from jvmci code.
> The commits are separate to help reviewing, but the entire change has been tested together with tier1-6.
> The commits in this change have been performance tested individually and together with no meaningful differences from mainline.

Thank you for the code review, David.

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PR: https://git.openjdk.java.net/jdk/pull/6336