This reverts commit 8a914846.

Reason for revert: Seems to cause layout test failures: https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8-Blink%2520Mac/16246

Original change's description:
> [wasm] Turn deferred handles into global handles
> 
> Each instance of {DeferredHandles} only stores a single handle anyway,
> so turning them into global handles saves memory.
> 
> R=​ahaas@chromium.org
> 
> Bug: v8:7921, v8:8423
> Change-Id: I75e0cc6ecb6d0337f1695e6bfd4b5fdcb8a2039c
> Reviewed-on: https://chromium-review.googlesource.com/c/1402715
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59331}

TBR=ahaas@chromium.org,clemensh@chromium.org

Change-Id: I8996fd22702b5dd0485e59b54989788596293a1f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7921, v8:8423
Reviewed-on: https://chromium-review.googlesource.com/c/1451888Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59342}