Change ART_TEST_GC_STRESS to use new gcstress mode

Enable new gcstress mode that checks at each allocation site
(with some tracking of stack traces to only do one check per
unique site).

Disable 137-cfi for gcstress, as it's sleeping to "synchronize"
with a forked process, which doesn't work with the slower mode.

Bug: 22014525
Change-Id: Ife70308e45b04f5d97267b4d98f8c75fa96492a1
2 files changed