This reverts commit b66993bc.

Reason for revert: Broke v8 win32 https://ci.chromium.org/p/v8/builders/ci/V8%20Win32/29454?

Original change's description:
> [code] Separate instruction and metadata areas
>
> In this CL, Code object layout changes s.t. the instruction
> area is distinct / non-overlapping from the metadata area.
>
> On-heap Code objects now have a variable-size `body` area,
> containing distinct-but-adjacent `instruction` and `metadata`
> areas.
>
> Off-heap code (= embedded builtins) currently have the same,
> but in the future the metadata area will move elsewhere and
> no longer be adjacent to instructions.
>
> To implement this, the main changes are:
>
>  - The Code object header now contains instruction and metadata
>    sizes, and no longer contains the safepoint table offset
>    (it's implicitly the first table of the metadata section).
>  - The embedded metadata table contains information about both
>    instruction and metadata areas.
>
> I've also added assertions in spots that currently rely on a
> contiguous body area.
>
> Bug: v8:11036
> Change-Id: I940f0c70c07ad511dafd2d2c3e337de8c92cd4b9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2491025
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70743}

TBR=jgruber@chromium.org,leszeks@chromium.org,clemensb@chromium.org,dinfuehr@chromium.org

Change-Id: Ia52ac609a47b8a2038a2511f0af8526ebdfe4719
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:11036
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2497381Reviewed-by: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70744}