Revert "Revert "ART: Give JIT thread pool workers a peer"" This reverts commit 9dfb707ba2f8c2ff67d42c26e3214f5d7142b6d3. Accept a live Java thread for the JIT, and adjust the tests accordingly. (cherry picked from commit 4471e4f7c5874bdaf93762b6047d4a4bebc465df) Bug: 31684920 Test: m ART_TEST_JIT=true ART_TEST_INTERPRETER=true test-art-host Change-Id: I92cbae1eaae05711b9069335cf1a5f7eb58b9fd8