ART: Use ThreadList RunCheckpoint for GetAllStackTraces

Move to using the ThreadList code to avoid races. The tradeoff is a more
complicated infrastructure to collect and store the traces.

Bug: 62353392
Test: m test-art-host
Test: art/test/testrunner/testrunner.py -b --host -t 911
Change-Id: I71e957dbfbd619f6cfa0cdd1e6cb894e25cf5483
1 file changed