log: remove increasing windows usage in fastpath
The purpose of increasing windows is to allow backwards iteration on the
filelog at a reasonable cost.
But is it needed?
- if follow is False, we have no reason to iterate backwards.
We basically just want to walk the complete filelog and yield all revisions
within the revision range. We can do this forward or
backwards, as it only reads the index.
- when follow is True, we need to examine the contents of the filelog, and to
do this efficiently we need to read the filelog forward.
And on the other hand, to track ancestors and copies, we need to process
revisions backwards. But is it necessary to use increasing windows
for this?
We can iterate over the complete filelog forward, stack the revisions, and
read the reversed(pile), it does the same thing with a more readable code.
adding dir/bar
adding foo
dir/bar
foo
committed changeset 0:d44511117907
adding dir/bar_2
adding foo_2
dir/bar_2
foo_2
committed changeset 1:a85812e0561a
adding a
adding c
removing a
adding b
removing c
adding d
recording removal of a as rename to b (100% similar)
removing a
adding b
removing c
adding d
recording removal of a as rename to b (100% similar)