Clean up some simulator management code.
Created attachment 427284 [details] Patch
Committed r276735 (237136@main): <https://commits.webkit.org/237136@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 427284 [details].
<rdar://problem/77288673>
Committed r278127 (238177@main): <https://commits.webkit.org/238177@main>