This reverts commit f589d561.

Reason for revert: failing win64 asan
https://ci.chromium.org/p/v8/builders/ci/V8%20Win64%20ASAN/8653

Original change's description:
> [torque] move class tests to unittests
> 
> This avoids the generation of fake external classes.
> 
> Bug: v8:7793
> Change-Id: I9744b299d3ec474d72b298b4f6143f95e345d1d9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1625991
> Reviewed-by: Simon Zünd <szuend@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61778}

TBR=sigurds@chromium.org,tebbi@chromium.org,szuend@chromium.org

Change-Id: I762f29a0d3212d2eabfafa48c0e46940d0e6f835
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7793
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1625863Reviewed-by: Francis McCabe <fgm@chromium.org>
Commit-Queue: Francis McCabe <fgm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61805}