changegroup: inline prune() logic from narrow
prune() needs to ellide manifests that aren't part of the narrow
matcher.
The code is violating storage abstractions, so a comment has been
added. Keep in mind the impetus for moving this code to core
is so changegroup code can be refactored to be storage agnostic.
Differential Revision: https://phab.mercurial-scm.org/D4012
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}