This reverts commit 5dee355f.

Reason for revert: https://ci.chromium.org/p/v8-internal/builders/luci.v8-internal.ci/v8_linux64_perf_1/4282

Original change's description:
> [test] add perf tests for String.p.startsWith
> 
> Add performance tests for String.prototype.startsWith ahead of port to
> torque in order to keep track of how performance is affected.
> 
> Bug: v8:8400
> Change-Id: Ifc753a6f13da20c1760e545a99fd693717e3acc6
> Reviewed-on: https://chromium-review.googlesource.com/c/1402934
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58685}

TBR=jgruber@chromium.org,usharma1998@gmail.com

Change-Id: I5855b08fa5e55ab8594185a0a84a26f567e2b9d3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8400
Reviewed-on: https://chromium-review.googlesource.com/c/1404446Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58697}