This reverts commit 6f763280.

Reason for revert: speculative revert for MSAN failure:
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/25398

Original change's description:
> [cleanup] Cleanup handling of padding field in Map
> 
> Bug: v8:8834
> Change-Id: Iae9cbcccb8747298c5680ac1e865efebee85acec
> Reviewed-on: https://chromium-review.googlesource.com/c/1480385
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59774}

TBR=ulan@chromium.org,ishell@chromium.org,verwaest@chromium.org

Change-Id: Icf42e4566382c8539c8d7fb709a91bf0c6353858
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8834
Reviewed-on: https://chromium-review.googlesource.com/c/1481025Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59776}