[wasm] Add shared field to memory type

R=thibaudm@chromium.org

Bug: v8:12227
Change-Id: If10683be63beb32c658d2dfaac0a07d858c472ba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3162038


Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76871}