bug#51734: 29.0.50; got slow

[Katsumi Yamaoka]

On Thu, 11 Nov 2021 10:09:30 +0200, Eli Zaretskii wrote:
>> Probably what I should do could be bisecting the recent commits.
> That'd be best, if you can.  Thanks.

I did it and found the revision that causes this problem on at
least Cygwin-64.  That is d5bb053.  However, as there are a lot
of changed files in a single commit, it seems hard to me to find
what change is the real cause.  I need a skillful Cygwin player.

Thanks.