This reverts commit a5fa211f.

Reason for revert: breaks ARM Lite builder:
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20arm%20-%20sim%20-%20lite/4843

Original change's description:
> [roheap] Check that ro-heap is always passed the same read-only snapshot
> 
> Previously the ReadOnlyHeap simply discarded all but the first
> ReadOnlyDeseralizer. ClearSharedHeapForTest should be called if using a
> new ReadOnlyDeserializer (this might change in the future).
> 
> Remove an obsolete 'StartupSerializerRootMapDependencies' test. It used
> to test Map::WeakCellForMap which doesn't exist anymore and was
> difficult to adapt to a shared read-only heap.
> 
> Bug: v8:7464
> Change-Id: I64b8e953b0e3466e003541ec8a9321e439a01d33
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1660612
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
> Cr-Commit-Position: refs/heads/master@{#62250}

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

Change-Id: I099544913bec3bbd67840b1818a6ad6029fdf380
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7464
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1666453Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62264}