wireproto: implement command executor interface for version 1 peers Now that we've defined our new interface for issuing commands, let's implement it. We add the interface to the base peer interface. This means all peer types must implement it. The only peer types that we have are the local peer in localrepo and a shared wire peer for version 1 of the wire protocol. The local peer implementation is pretty straightforward. We don't do anything fancy and just return a resolved future with the result of a method call. This is similar to what localiterbatcher does. The wire protocol version 1 implementation is a bit more complicated and is a more robust implementation. The wire executor queues commands by default. And because the new executor interface always allows multiple commands but not all version 1 commands are @batchable, it has to check that the requested commands are batchable if multiple commands are being requested. The wire executor currently only supports executing a single command. This is for simplicity reasons. Support for multiple commands will be added in a separate commit. To prove the new interface works, a call to the "known" command during discovery has been updated to use the new API. It's worth noting that both implementations require a method having the command name to exist on the peer. There is at least one caller in core that don't have a method calls peer._call() directly. We may need to shore up the requirements later... Differential Revision: https://phab.mercurial-scm.org/D3268