This reverts commit c1ea574e.

Reason for revert: We'd need to investigate on a range of hardware
generations to assess if this is a good change; in general new
hardware (intel 9th gen / amd ryzen) seems to be happier with
xchg, while older hardware is not happy with xchg.

Original change's description:
> [codegen] Use xchg instead of push/pop for swap
>
> R=​sigurds@chromium.org
>
> Change-Id: Id22a44fa15827d5c076496d872fe3be7da360b5e
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1678356
> Auto-Submit: Thibaud Michaud <thibaudm@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62383}

TBR=sigurds@chromium.org,thibaudm@chromium.org

Change-Id: Ieecbbc21fa7094fdfd190b266f6d8486ee8611b8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1679494Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62404}