graft: do not use `.remove` on a smart set (regression)

Revset calls use to return a list. Graft use to mutate that list. We cannot do
this anymore leading to a crash when grafting multiple changeset with a revset.

    File ".../mercurial/commands.py", line 3117, in graft
      revs.remove(rev)
    AttributeError: '_addset' object has no attribute 'remove'

We are late in code-freeze so we make the shortest possible fix by turning it
back to a list.

--HG--
branch : stable
revset: fix revision filtering in spanset.contains (regression)

The argument is `x` but the variable tested for filtering is `rev`. `rev`
happens to be a revset methods, ... never part of the filtered revs. This
method is now using `rev` for everything.

--HG--
branch : stable
revsetbenchmark: fix error raising

We want to display the commands, not all arguments of the function. (The old
code actually crash, failing to joining a list of lists.)

--HG--
branch : stable
ancestor: silence multiple ancestor warning outside of merge (issue4234)

The current situation is a bit of a layering violation as
merge-specific knowledge is pushed down to lower layers and leaks
merge assumptions into other code paths.

Here, we simply silence the warning with a hack. Both the warning and
the hack will probably go away in the near future when bid merge is
made the default.

--HG--
branch : stable
revset: inline spanset containment check (fix perf regression)

Calling a function is super expensive in python. We inline the trivial range
comparison to get back to more sensible performance on common revset operation.

Benchmark result below:

Revision mapping:
0) 3f83fc5cfe71 2.9.2 release
1) bcfd44abad93 current @
2) This revision


revset #0: public()
0) wall 0.010890 comb 0.010000 user 0.010000 sys 0.000000 (best of 201)
1) wall 0.012109 comb 0.010000 user 0.010000 sys 0.000000 (best of 199)
2) wall 0.012211 comb 0.020000 user 0.020000 sys 0.000000 (best of 197)

revset #1: :10000 and public()
0) wall 0.007141 comb 0.010000 user 0.010000 sys 0.000000 (best of 361)
1) wall 0.014139 comb 0.010000 user 0.010000 sys 0.000000 (best of 186)
2) wall 0.008334 comb 0.010000 user 0.010000 sys 0.000000 (best of 308)

revset #2: draft()
0) wall 0.009610 comb 0.010000 user 0.010000 sys 0.000000 (best of 279)
1) wall 0.010942 comb 0.010000 user 0.010000 sys 0.000000 (best of 243)
2) wall 0.011036 comb 0.010000 user 0.010000 sys 0.000000 (best of 239)

revset #3: :10000 and draft()
0) wall 0.006852 comb 0.010000 user 0.010000 sys 0.000000 (best of 383)
1) wall 0.014641 comb 0.010000 user 0.010000 sys 0.000000 (best of 183)
2) wall 0.008314 comb 0.010000 user 0.010000 sys 0.000000 (best of 299)

We can see this changeset gains back the regression for `and` operation on
spanset.  We are still a bit slowerfor the `public()` and `draft()`. Predicates
not touched by this changeset.

--HG--
branch : stable
revset: also inline spanset._contained in __len__

For consistency with what happen in `__contains__`, we inline the range test
into `__len__` too.

--HG--
branch : stable