Revert "Revert "Workaround for the Tern crash.""

This reverts commit 0ae195f6ef3fb0c446802800af94d98c470d5015.
temporarily switch to my tern
turn off optimization in acorn (but not acorn_loose right now)
Merge pull request #4595 from adobe/dangoor/v8-crash-redux

v8 crash (acorn parsing) workaround