Merge "ART: Check whether an oat file exists before opening" am: d9d54c57e0
am: 6b44e4b69a

* commit '6b44e4b69aeea90471742bcff2de7fb4a009c2fb':
  ART: Check whether an oat file exists before opening

Change-Id: I673e55572a92fa8e7bbece0eee987888533ea78f