Teaches git to normalize pathnames read from readdir(3) and all
arguments from the command line into precomposed UTF-8 (assuming
that they come as decomposed UTF-8) to work around issues on Mac OS.
I think there still are other places that need conversion
(e.g. paths that are read from stdin for some commands), but this
should be a good first step in the right direction.
* tb/sanitize-decomposed-utf-8-pathname:
git on Mac OS and precomposed unicode
b856ad623e