Remove a spurious assert probably introduced by a bad merge that
disallowed RO_SPACE sharing when pointer compression is enabled.

Change-Id: I8a59a242667252dcbb098e5be405ac67a4e01a3d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2445877
Auto-Submit: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70290}