[Core] Fix event loop instrumentation causing Java segfaults in tests. (#15349)
[Core] Fix event loop instrumentation causing Java segfaults in tests. (#15349)

* Reenable event loop instrumentation.

* Take stats handle by copy in post() handler closure.

* Revert "Take stats handle by copy in post() handler closure."

This reverts commit e46777939bcc3bb4bb101e136e9d3348ea4ae1a1.
ray-project/ray,ray-project/ray,pcmoritz/ray-1,ray-project/ray,pcmoritz/ray-1,pcmoritz/ray-1,pcmoritz/ray-1,pcmoritz/ray-1,ray-project/ray,pcmoritz/ray-1,ray-project/ray,ray-project/ray,pcmoritz/ray-1,ray-project/ray,ray-project/ray,pcmoritz/ray-1