This reverts commit 556f44c4.

Reason for revert: Test fatally OOMs on ARM. https://ci.chromium.org/p/v8/builders/ci/V8%20Arm/12336

Original change's description:
> [strings] Fix hash for exactly 512MB long strings
> 
> Bug: chromium:1016237
> Change-Id: Idda1e44b5d578d1213aa54927ca68289bcdce8ac
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1878487
> Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#64552}

TBR=jkummerow@chromium.org,ishell@chromium.org

Change-Id: Ia942469346b0f11fcf853d21717fd127815f7fba
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1016237
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1879669Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64553}