This reverts commit ef2a19a2.

Reason for revert: Broken layout tests: https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_chromium_rel_ng/201392

Original change's description:
> Add fast path for spreading primitive strings.
> 
> This improves the performance on primitive strings of
> IterableToListWithSymbolLookup, which implements the
> CreateArrayFromIterable bytecode. The fast path is only
> taken if the string iterator protector is valid (that is,
> String.prototype[Symbol.iterator] and
> String.prototype[Symbol.iterator]().next are untouched).
> 
> This brings spreading of primitive strings closer to the
> performance of the string iterator optimizations.
> (see https://docs.google.com/document/d/13z1fvRVpe_oEroplXEEX0a3WK94fhXorHjcOMsDmR-8/).
> 
> Bug: chromium:881273, v8:7980
> Change-Id: Ic8d8619da2f2afcc9346203613a844f62653fd7a
> Reviewed-on: https://chromium-review.googlesource.com/1243110
> Commit-Queue: Hai Dang <dhai@google.com>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56329}

TBR=ulan@chromium.org,neis@chromium.org,sigurds@chromium.org,bmeurer@chromium.org,dhai@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: chromium:881273, v8:7980
Change-Id: I4868160b87bdebf9fd2ff346aefd4cdce23681a1
Reviewed-on: https://chromium-review.googlesource.com/c/1261022Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56365}