Matt Harbison <matt_harbison@yahoo.com> [Tue, 08 Nov 2022 13:38:06 -0500] rev 49596
typing: fix a syntax error in mercurial/cext/bdiff.pyi
I noticed because `merge-pyi` on the non-cext implementations with this file as
input skipped the return type for this. `pytype-single --parse-pyi` confirmed
it was a problem.