cleanup: migrate from re.escape to stringutil.reescape...
cleanup: migrate from re.escape to stringutil.reescape
This has consistent behavior on Python 2.7, 3.6, and 3.7 and has the
benefit of probably being a little faster. Test output changes are
largely because / used to be pointlessly escaped.
Differential Revision:
https://phab.mercurial-scm.org/D3842