This adds a very first version of inlined Array.prototype.pop into
TurboFan optimized code. We currently limit the inlining to fast
object or smi elements, until the unclear situation around hole NaNs
is resolved and we have a clear semantics inside the compiler.

It's also probably overly defensive in when it's safe to inline
the call to Array.prototype.pop, but we can always extend that
later once we have sufficient trust in the implementation and see
an actual need to extend it.

BUG=v8:2229,v8:3952,v8:5267
R=epertoso@chromium.org

Review-Url: https://codereview.chromium.org/2239703002
Cr-Commit-Position: refs/heads/master@{#38578}