locking: take the `wlock` for the full `hg addremove` duration
Otherwise, there is a race condition window between the time we resolve the
file to addremove with the matcher and the time we lock the repo and modify the
dirstate.
For example, the working copy might have been updated away, or purged, and the
matched files would no longer be correct.
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).