rust-chg: reimplement run_command operation as async function...
rust-chg: reimplement run_command operation as async function
The crafted state machine is no longer needed thanks to async/await.
The state machine is basically rewritten as follows:
- Ready(..) -> return ..
- PollAgain(..) -> run .. and await
- Err(..) -> return Err(..)
Differential Revision:
https://phab.mercurial-scm.org/D8445
