fix: use scmutil.movedirstate() instead of reimplementing I wrote this patch 2 years ago as a little cleanup. I wanted to generally used `scmutil.movedirstate()` instead of manually updating the dirstate because that is easy to get wrong. I didn't know until today that the current code had a bug. So I added the test case two patches before this one and dusted off this one patch. This is a little slower than the previous code, as it diffs two manifests. However, it fixes the bug and I don't think it's going to be noticeably slower anyway. Differential Revision: https://phab.mercurial-scm.org/D11210