Mostly fix Mac CMake build
Created attachment 439416 [details] Patch
Note that there are important steps to take when updating ANGLE. See https://trac.webkit.org/wiki/UpdatingANGLE
Committed r283174 (242222@main): <https://commits.webkit.org/242222@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 439416 [details].
<rdar://problem/83625794>