WHLSL functions automatically do null checks, but the native functions don't.
Created attachment 350536 [details] Patch
Committed r236388: <https://trac.webkit.org/changeset/236388>
<rdar://problem/44708648>
Migrated to https://api.github.com/repos/gpuweb/WHLSL/issues/29
https://github.com/gpuweb/WHLSL/issues/29