In preparation for a modern evaluator.
<rdar://problem/101239718>
Created attachment 463025 [details] Patch
Created attachment 463026 [details] Patch
Created attachment 463027 [details] Patch
Committed 255622@main (6cfcd648cf58): <https://commits.webkit.org/255622@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 463027 [details].