The inline allocation sequence in the optimizing compilers cannot deal
well with funky types like JSRegExp, which have some magic fields in
addition to the inobject properties. In Crankshaft we already use the
FastNewObjectStub for %_NewObject in general, so fix TurboFan to the same.
Hopefully one day we can kill %_NewObject completely.

R=jarin@chromium.org
BUG=chromium:609029
LOG=n

Review-Url: https://codereview.chromium.org/1943403004
Cr-Commit-Position: refs/heads/master@{#36006}