perf: add option to perfstatus to get the status of unknown files
When status needs to look at unknown files (e.g. when running hg status), it
needs to use a completely different algorithm than when it doesn't (e.g. when
running hg diff).
dirstate: test normalize is truthy instead of using a no-op lambda
hg perfstatus -u on a working directory with 170,000 files, without this
change:
! wall 1.869404 comb 1.850000 user 1.170000 sys 0.680000 (best of 6)
With this change:
! wall 1.839561 comb 1.830000 user 1.120000 sys 0.710000 (best of 6)