context: drop a redundant fast path in introrev
Now that _adjustlinkrev fast path this case itself, we no longer need an extra
conditional.
A nice side effect is that we are no longer calling `self.rev()`. In case
where `_descendantrev` is set, calling `self.rev` will trigger a potentially
expensive `_adjustlinkrev` call. So blindly calling `self.rev()` to avoid
another `_adjustlinkrev` call can be counterproductive.
Note that `_descendantrev` is currently never taken into account in `introrev`
so far which is wrong. We'll fix that in changeset later in this series.
graft c-ext
graft zstd
graft tests
include make_cffi.py
include setup_zstd.py
include zstd.c
include LICENSE