Merge "ART: Check whether an oat file exists before opening" into nyc-dev
am: 1e8a22fa84

* commit '1e8a22fa849119aa8ea24b3811e74dea12bdb8c3':
  ART: Check whether an oat file exists before opening

Change-Id: I560e6cf682661b83394a5d6298afd9b7159b4033