This reverts commit 21e34c71.

Reason for revert: breaks TSAN https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20TSAN/27444

Original change's description:
> [cleanup][test] split es6/classes.js into different tests
> 
> es6/classes.js is large and causes timeouts and OOM on some of the
> configurations.
> 
> Bug: v8:9246
> Change-Id: Iaabfc39dd8f9554e16f67d66ce64acd3dd56b9ee
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1704103
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Commit-Queue: Mythri Alle <mythria@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62758}

TBR=mythria@chromium.org,gsathya@chromium.org

Change-Id: I296d51ed682f51a3e6794858ab96b9407cc8ec56
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9246
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1706058Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62760}