This reverts commit dac86be2.

Reason for revert: Still failing msan: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/26904

Original change's description:
> Reland "[heap] Add global memory controller"
> 
> Provide a global memory controller used to compute limits for combined
> on-heap and embedder memory. The global controller uses the same
> mechanism (gc speed, mutator speed) and growing factors as the regular
> on-heap controller.
> 
> Rely on V8's mechanisms for configured state that stops shrinking the
> limit.
> 
> This reverts commit 5e043f27.
> 
> Tbr: ulan@chromium.org
> Bug: chromium:948807
> Change-Id: Id4f94e7dcb458d1d0d2f872194f8f3ea0959a73f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622968
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61715}

TBR=ulan@chromium.org,mlippautz@chromium.org

Change-Id: If30649f158a08fd185f2771a13b8e09cf53fb667
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:948807
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1622849Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61716}