D1606: phases: drop the list with phase of each rev, always comput phase sets

[quark (Jun Wu)]

quark added inline comments.

INLINE COMMENTS

> yuja wrote in phases.py:236
> Nit: could be written as `fullrepoest(repo) - baseset(revs)`.

`baseset.__contains__` is slower than `set.__contains__` so the current code is faster.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D1606

To: joerg.sonnenberger, #hg-reviewers, quark, yuja
Cc: yuja, durin42, quark, mercurial-devel