Start allocating shared memory with MAP_MEM_VM_SHARE again on newer OSes, since MAP_MEM_VM_SHARE no longer prevents memory attribution.
<rdar://problem/94032696>
Pull request: https://github.com/WebKit/WebKit/pull/1095
Committed r294951 (251059@main): <https://commits.webkit.org/251059@main> Reviewed commits have been landed. Closing PR #1095 and removing active labels.