The predicate in question used to report true on both, Crankshaft and
TurboFan code. It has hence become obsolete and can be replaced by the
existing {Code::is_turbofanned} predicate. This also frees up a bit in
the second kind-specific bit field.

R=jarin@chromium.org
BUG=v8:6408

Change-Id: I204d7dd78a639c752c9749fd305c7006c6b6aca3
Reviewed-on: https://chromium-review.googlesource.com/599868Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47125}