dirstate: add a C implementation for nonnormalentries Before this patch, there was only a python version of nonnormalentries. On mozilla-central we have a 10x win by putting this function in C: % python -m timeit -s \ 'from mercurial import hg, ui, parsers; \ repo = hg.repository(ui.ui(), "mozilla-central"); \ m = repo.dirstate._map' \ 'parsers.nonnormalentries(m)' 100 loops, best of 3: 3.15 msec per loop The python implementation runs in 31ms, a similar test gives: 10 loops, best of 3: 31.7 msec per loop On our big repos, the win is still of 10x with the python implementation running in 350ms and the C implementation running in 30ms.