Hook up TurboFan with the existing field type tracking machinery to
eliminate redundant map checks on the results of LoadField operators.
The store side is already implemented in TurboFan for quite some time,
this just adds the load part.

R=jarin@chromium.org
BUG=v8:5267

Review-Url: https://codereview.chromium.org/2604393002
Cr-Commit-Position: refs/heads/master@{#42015}