According to WebAssembly's thread proposal, the memory type is decided
at the Object's creation and don't change over time.

When growing a shared memory and the old buffer was marked as shared;
setup the new buffer as shared as well.

Bug: v8:8564
Change-Id: I7e59071d11b41315429232ae0c90436c6810bd0e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1526012Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Sven Sauleau <ssauleau@igalia.com>
Auto-Submit: Sven Sauleau <ssauleau@igalia.com>
Cr-Commit-Position: refs/heads/master@{#60312}