disrstate._check(link|exec) modifies repo dir mtime

[Yuya Nishihara]

On Sat, 1 Oct 2016 11:35:40 -0700, Dorian Taylor wrote:
> is there a reason why all this testing can’t go on in $REPO/.hg?

No idea why, but there was an attempt to move check* files to .hg/cache.

https://www.mercurial-scm.org/pipermail/mercurial-devel/2015-October/074885.html
https://www.mercurial-scm.org/pipermail/mercurial-devel/2015-November/074971.html

Per mpm's comment, we can move check* files out of the repo root.