typing: explicitly set the return type of `_InnerRevLog.raw_text()`
Somewhere between
cd72a88c5599 and
2fd44b3dcc33, pytype changed the return type
from `Tuple[_T1, Any, bool]` to `Any`. Both are wrong. `mdiff.patches()` is an
alias for `mpatch.patches()`, which is selected via module policy (and breaks
the ability to infer the types). However, `cext`, `cffi`, and `pure`
implementations all agree it returns bytes.
#require docutils gettext
$ $TESTDIR/check-gendoc ru
checking for parse errors