This reverts commit d37f6fd6.

Reason for revert:
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux%20-%20gc%20stress/19643

Original change's description:
> [Intl] Handle invalid values in locale
> 
> Fix the bug that we call setKeywordValue w/o convert the key to legacy key.
> 
> Bug: v8:7481
> Change-Id: I5a743e41d02b64385c5050fc1d83279741e24659
> Reviewed-on: https://chromium-review.googlesource.com/c/1339243
> Commit-Queue: Frank Tang <ftang@chromium.org>
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Reviewed-by: Jungshik Shin <jshin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#57886}

TBR=jshin@chromium.org,gsathya@chromium.org,ftang@chromium.org

Change-Id: I3765eed7a9bdf123321c6d0589dfb72ab8ae2b2f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7481
Reviewed-on: https://chromium-review.googlesource.com/c/1352284Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57888}