byteify-strings: handle multi-line strings in _ensuresysstr
The current implementation did not handle calls like
`repo.ui.log("first line"
"other line")`
correctly.
Danny Hooper <hooper@google.com> [Wed, 22 May 2019 16:22:06 -0700] rev 42673
fix: run fixer tools in the repo root as cwd so they can use the working copy
This lets fixer tools do things like find configuration files, with the caveat
that they'll only see the version of that file in the working copy, regardless
of what revisions are being fixed.
Differential Revision: https://phab.mercurial-scm.org/D6440