narrow: move status-filtering to core and to ctx One of my recent changes from repo.status(ctx1, ctx2) to ctx1.status(ctx2) broke some of our Google-internal tests. The problem turned out to be that the narrow extension was overriding repo.status() to make it filter out paths outside the narrowspec. When I changed to ctx1.status(ctx2), then that filtering obviously got lost. ctx.status() seems like a better method to do the filtering in, so this patch moves the filtering into that method, thereby also moving it out of the extension and into core. Differential Revision: https://phab.mercurial-scm.org/D4068