Treat redirection of standard handles on Windows as it is done on Unix.

* job.c (start_job_command) [WINDOWS32]: Compute outfd and errfd
as on Posix platforms, and pass the results to process_easy.
* function.c (windows32_openpipe) [WINDOWS32]: Accept an
additional argument ERRFD and use it for redirecting the standard
error handle passed to the subprocess.
(func_shell_base) [WINDOWS32]: Pass the computed errfd to
windows32_openpipe.
2 files changed