narrow: reuse narrowspec.updateworkingcopy() when narrowing Similar to the previous patch for widening, but here we also need to teach updateworkingcopy() to forcefully delete files that are not recorded in the dirstate as clean. That should be safe because the narrowing command (e.g. `hg tracked --removeinclude`) has already checked that the working copy is clean. Differential Revision: https://phab.mercurial-scm.org/D5511