Allow HDeoptimize to co-exist with LSE.

The env use of HDeoptimize counts as escaping at the end of
executing the compiled code for a singleton, just like a return.
So store elimination won't happen for that singleton's locations.

Test: make test-art-host
Bug: 31716107

Change-Id: I09838e80586d279714c676a2f7294ae518f61457