This improves type safety, gives the optimizer more information to work with, and generally makes more sense (an AccessibilityObject should never be able to return the other AXCoreObject variant, AXIsolatedObject).
<rdar://problem/116625342>
Created attachment 468105 [details] Patch
Created attachment 468108 [details] Patch
Created attachment 468111 [details] Patch
Committed 269055@main (3cf70a3a5727): <https://commits.webkit.org/269055@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 468111 [details].