This CL renames InterpreterPushArgsMode::kJSFunction to kArrayFunction
because we only ever use it for the array function.

We never use PushArgsThenCall with kArrayFunction mode, so remove the
unused helpers that provide the plumbing there.

This is in preparation for changes to PushArgsThenConstruct, where we
will no longer pass the allocation site as undefined for modes other
than kArrayFunction.

Bug: v8:7503
Change-Id: I86e3333e2ebd912fc8f9b0e4248282330af4b9e2
Reviewed-on: https://chromium-review.googlesource.com/972047
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Mythri Alle <mythria@google.com>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52109}