amend: update .hgsubstate before committing a memctx (
issue5677)
This is a minimal copy of localrepo.commit(). As the current amend() function
heavily depends on the wctx API, it wasn't easy to port it to use a separate
status tuple. So for now, wctx._status is updated in-place.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}