Revert of [cleanup] Refactor builtins-number.cc (patchset #2 id:40001 of https://codereview.chromium.org/2517833005/ )

Reason for revert:
Secondary dependency to revert https://codereview.chromium.org/2522393002/

Original issue's description:
> [cleanup] Refactor builtins-number.cc
>
> Introducing a TF_BUILTIN macro that wraps CodeStubAssembler usage
> into a convenient interface (using a subclass under the hood).
>
> Committed: https://crrev.com/cbf59c4c704e83a43b52c5ba6825df576fdaece8
> Cr-Commit-Position: refs/heads/master@{#41236}

TBR=ishell@chromium.org,jkummerow@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2529873002
Cr-Commit-Position: refs/heads/master@{#41252}