CreateProcess: add stdin/out/err redirection

CreateProcess: add stdin/out/err redirection

When launching a new process stdin/stdout/stderr can be redirected by
passing the corresponding HANDLEs in the passed lpStartupInfo structure.
This is required for example if a pipe should be used as stdin/stdout.

If set in lpStartupInfo the file descriptor of the passed handle is
now used. The test was updated accordingly.