The patch on this bug is being broken up into multiple changes, but should be sufficient to build watchOS and tvOS both Simulator and device with a public SDK.
I have verified the following all work:
build-webkit --wathos-device
build-webkit --wathos-simulator
build-webkit --tvos-device
build-webkit --tvos-simulator
CI + EWS has confirmed I haven't broken iOS. I think it's time to close this bug!
2020-06-04 10:03 PDT, Jonathan Bedard