evolve: add test to demonstrate issue6203
Current logic of content-divergence resolution contains a bug that
if resolution parent is not the parent of any of the two divergent
changesets, it could undo some changes.
I think a good solution for this is to first relocate the divergent cset
to it's obsolete parent's successor if applicable and then perform
the content-divergence resolution.
Next patch will fix the issue.
{"pattern": "glob:hgext3rd/**/*.py", "tool": "byteify-strings"}