This reverts commit b88e7d21.

Reason for revert: Speculative revert for:
https://ci.chromium.org/p/v8/builders/ci/V8%20Blink%20Linux/7243

Original change's description:
> [wasm] Share export wrappers across modules
>
> Add a map in {IsolateInfo} to share export wrappers across modules. Each
> entry is a weak handle which uses the finalizer to remove itself from
> the map after the last strong reference dies.
>
> R=​clemensb@chromium.org
>
> Bug: chromium:862123
> Change-Id: I1f3a6af6aa4c4e42abfe587354ca14f9da916d91
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2448465
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70348}

TBR=ulan@chromium.org,clemensb@chromium.org,thibaudm@chromium.org

Change-Id: I5ccf4830301939b2b5d7a0d0d769ab9b90536619
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:862123
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2453730Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70358}