Summary:
I did a local comparison between using bash and using lit's runner, and
more of the suite passes with lit than passes with bash. Most of the
bash failures have to do with /dev/null, which is nonsensical on
Windows, but the lit runner handles it.
The lit shell runner is also much faster than bash, so I would expect
most Windows devs would want it by default.
The behavior can be overridden on any OS by setting
LIT_USE_INTERNAL_SHELL to 0 or 1 in the environment.
Reviewers: chapuni, ddunbar
CC: llvm-commits, timurrrr
Differential Revision: http://llvm-reviews.chandlerc.com/D559
llvm-svn: 179173
d16abb7732