The urgent argument is a platform-specific flag that leaked into the (ideally) platform-independent HTTP/2 transport layer. In an effort to clean up the cross-platform API surface, it would be helpful if we can remove this argument from the TCP Read api without losing the performance optimization that was introduced along with it (see #18240).
- Pass extra param to grpc_endpoint_read() as the API has changed.
- Fixed build error seen with Xcode 10.
- Enable pipefail to xcodebuild errors are propagated to the caller.