This changes the existing cctest/test-field-type-tracking tests to
use actual Code objects and proper code dependencies to test that the
runtime actually does the right thing (aka deoptimizes the Code objects
correctly). Before it was using the CompilationDependencies, which as
of now no longer check whether the runtime actually deoptimized or not.

This is a prerequisite for changing the way we handle field representation
changes, specifically going from Smi or HeapObject to Tagged.

Bug: v8:8749, v8:8865
Change-Id: I260294217550cee2b42f7ba7e9c92bf0d1db0b8c
Doc: http://bit.ly/v8-in-place-field-representation-changes
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1557149
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60686}