restart coprocess in raw mode

restart coprocess in raw mode

Restarting a crashing git process could result in filename encoding issues
when not in a unicode locale, as the restarted processes's handles were not
read in raw mode.

Since rawMode is always used when starting a coprocess, didn't bother
to parameterise it and just always enable it for simplicity.

This commit was sponsored by Jake Vosloo on Patreon.