This reverts commit 4e1d7c87.

Reason for revert:
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux%20-%20arm%20-%20sim%20-%20debug/14986

Original change's description:
> [wasm] Split compilation in three stages
> 
> In order to refactor ownership between objects in wasm compilation, the
> compilation (executed by background tasks) is split in three stages:
> getting a compilation unit (while holding a mutex), executing the work
> (without any mutex and without keeping the NativeModule alive), and
> submitting the work (with a mutex again).
> 
> This CL prepares this design by splitting compilation from submission.
> Both steps are still executed right after each other. This will be
> changed in a follow-up CL.
> 
> R=​titzer@chromium.org
> CC=​mstarzinger@chromium.org
> 
> Bug: v8:8689
> Change-Id: I2f92aee8e2f2d45470d8c63314ed026341630902
> Reviewed-on: https://chromium-review.googlesource.com/c/1414920
> Reviewed-by: Ben Titzer <titzer@chromium.org>
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58929}

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

Change-Id: Ic3d0287b354ef5f834b76bc2cdc096d2231f4477
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8689
Reviewed-on: https://chromium-review.googlesource.com/c/1422917Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58932}