patch: unify check_binary and binary flags
Follows up
079b27b5a869. If opts.text=True, check_binary is ignored, so we
can just pass the binary flag to unidiff().
perfunidiff now takes any inputs as text files, which I think is a desired
behavior.
fileset: don't abort when running copied() on a revision with a removed file
It looks like AND with any status-y fileset would trigger this, as added() and
removed() also failed. The 4.5-rc revision is a convenient test case, but the
merge isn't necessary.
py3: make sure we open the file in bytes mode
# skip-blame because we are just adding b
Differential Revision: https://phab.mercurial-scm.org/D2077