revlog: add attribute on revlogs that specifies its kind The sidedata logic needs to check whether the revlog it's working on is a changelog, a manifest or a filelog. Furthermore, future versions of the revlog format will most likely see a split between the three types (i.e. they will store different information), so having this will be useful for other future endeavors as well. Differential Revision: https://phab.mercurial-scm.org/D10151

--- a/mercurial/filelog.py	Fri Feb 19 10:53:27 2021 +0100
+++ b/mercurial/filelog.py	Wed Mar 10 19:33:18 2021 +0100
@@ -32,6 +32,7 @@
         # Full name of the user visible file, relative to the repository root.
         # Used by LFS.
         self._revlog.filename = path
+        self._revlog.revlog_kind = b'filelog'
 
     def __len__(self):
         return len(self._revlog)