bundlerepo: fix mismatches with repository and revlog classes

Both pytype and PyCharm complained that `write()` and `_write()` in the
bundlephasecache class aren't proper overrides- indeed they seem to be missing
an argument that the base class has.

PyCharm and pytype also complained that the `revlog.revlog` class doesn't have a
`_chunk()` method.  That looks like it was moved from revlog to `_InnerRevlog`
back in e8ad6d8de8b8, and wasn't caught because this module wasn't type checked.
However, I couldn't figure out a syntax with `revlog.revlog._inner._chunk(self, rev)`,
as it complained about passing too many args.  `bundlerevlog._rawtext()` uses
this `super(...)` style to call the super class, so hopefully that works, even
with the wonky dynamic subclassing.  The revlog class needed the `_InnerRevlog`
field typed because it isn't set in the constructor.

Finally, the vfs type hints look broken.  This initially failed with:

    File "/mnt/c/Users/Matt/hg/mercurial/bundlerepo.py", line 65, in __init__: Function readonlyvfs.__init__ was called with the wrong arguments [wrong-arg-types]
             Expected: (self, vfs: mercurial.vfs.vfs)
      Actually passed: (self, vfs: Callable)
    Called from (traceback):
      line 232, in dirlog
      line 214, in __init__

I don't see a raw Callable, but I tried changing some of the vfs args to be typed
as `vfsmod.abstractvfs`, but that class doesn't have `options`, so it failed
elsewhere.  `readonlyvfs` isn't a subclass of `vfs` (it's a subclass of
`abstractvfs`), so I'm not sure how to handle that.  It would be a shame to have
to make a union of vfs subclasses (but not all of them have `options` either).

mercurial/bundlerepo.py

@@ -55,7 +55,11 from .revlogutils import (
 
 
 class bundlerevlog(revlog.revlog):
-    def __init__(self, opener, target, radix, cgunpacker, linkmapper):
+    def __init__(
+        self, opener: typing.Any, target, radix, cgunpacker, linkmapper
+    ):
+        # TODO: figure out real type of opener
+        #
         # How it works:
         # To retrieve a revision, we need to know the offset of the revision in
         # the bundle (an unbundle object). We store this offset in the index
@@ -124,7 +128,7 class bundlerevlog(revlog.revlog):
         # delta base, not against rev - 1
         # XXX: could use some caching
         if rev <= self.repotiprev:
-            return revlog.revlog._chunk(self, rev)
+            return super(bundlerevlog, self)._inner._chunk(rev)
         self.bundle.seek(self.start(rev))
         return self.bundle.read(self.length(rev))
 
@@ -265,10 +269,10 class bundlephasecache(phases.phasecache
         if hasattr(self, 'opener'):
             self.opener = vfsmod.readonlyvfs(self.opener)
 
-    def write(self):
+    def write(self, repo):
         raise NotImplementedError
 
-    def _write(self, fp):
+    def _write(self, repo, fp):
         raise NotImplementedError
 
     def _updateroots(self, repo, phase, newroots, tr, invalidate=True):

mercurial/revlog.py

@@ -1310,6 +1310,7 class revlog:
     """
 
     _flagserrorclass = error.RevlogError
+    _inner: "_InnerRevlog"
 
     opener: vfsmod.vfs