This reverts commit c7c5b492.

Reason for revert: Looks like test needs to be disabled for noi18n: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux%20-%20noi18n%20-%20debug/40832/overview

Original change's description:
> [scanner] Combine surrogate pairs at start when scanning private names
>
> Bug: v8:12523
> Change-Id: Ic3779fe6f20965d177d99d0a570a735df72e4fde
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3366994
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#78493}

Bug: v8:12523
Change-Id: I678d69a7acb793ed03ce049a05c37685d0cdee1a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3368106
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#78495}