This reverts commit 24ac9a9a.

Reason for revert: compilation failures on windows. See https://ci.chromium.org/p/v8/builders/ci/V8%20Win32%20-%20builder/29313

Original change's description:
> Reland "[roheap] Enable shared ro-heap by default if ptr compression is disabled"
> 
> This is a reland of fb4d5480
> 
> Few test-serialize tests were not clearing the shared heap before using a
> new snapshot, breaking the noembed build. This is fixed now and a check
> has been added
> (https://chromium-review.googlesource.com/c/v8/v8/+/1667415) to make
> sure it doesn't happen again.
> 
> Original change's description:
> > [roheap] Enable shared ro-heap by default if ptr compression is disabled
> >
> > Shared read-only heap is currently incompatible with pointer compression.
> > Enable sharing only if pointer compression is disabled.
> >
> > Bug: v8:7464
> > Change-Id: I0866ac288a34eb92fc227e8beba57f4d72a69ef0
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1635509
> > Reviewed-by: Dan Elphick <delphick@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> > Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
> > Cr-Commit-Position: refs/heads/master@{#61963}
> 
> Bug: v8:7464
> Change-Id: Ie7d09cebf897a3f0e4a6c103ad0c132c4faf6c6e
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1667418
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
> Cr-Commit-Position: refs/heads/master@{#62425}

TBR=delphick@chromium.org,goszczycki@google.com

Change-Id: Ia96e2f13b502f96315ac2ed3447373c7b5774c6a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7464
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1680659Reviewed-by: Francis McCabe <fgm@chromium.org>
Commit-Queue: Francis McCabe <fgm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62426}