fuzz: exercise more of the revlog API I noticed in the coverage report that we didn't have much coverage in revlog.py. Let's try and get some of the more interesting bits tested by the fuzzer. I ran this locally for a few minutes to verify that I appear to be calling the various functions in reasonable ways. Differential Revision: https://phab.mercurial-scm.org/D5641

fuzz: don't allow enormous revlog inputs either I'm about to make the fuzzer do more, and without this it was getting enthusiastic about large (and therefore slow) inputs that I don't think buy us much. Differential Revision: https://phab.mercurial-scm.org/D5640

ui: remove unreachable branches and function calls from write() (issue6059) This is at least faster than ui.write() of 4.8.2. $ HGRCPATH=/dev/null hg files -R mozilla-central --time >/dev/null 4.8.2: time: real 2.340 secs (user 2.310+0.000 sys 0.020+0.000) 4.9rc0: time: real 2.580 secs (user 2.550+0.000 sys 0.020+0.000) this: time: real 2.230 secs (user 2.210+0.000 sys 0.020+0.000) Maybe the formatter should own a resolved write() function because it will just call dest.write(msg) most of the time, but that would be too much for stable.

ui: inline _writenobuf() into write() due to performance issue I'll remove redundant conditions later in this series.