w32: Change spawn functions to use Unicode version of CreateProcess.
* common/exechelp-w32.c (gnupg_spawn_process): Change to use CreateProcessW. (gnupg_spawn_process_fd): Ditto. (gnupg_spawn_process_detached): Ditto. * g10/exec.c (w32_system): Ditto.
We do not use this weirdo CREATE_UNICODE_ENVIRONMENT flag because it
does not make any sense to have non-ASCII names in the environment. I
can't imagine why this should be used at all and rationale for this
API features is, well, sparse.
(cherry picked from commit cf2f6d8a3f0594c03c383b4989a3041e9c4536d7)
- GnuPG-bug-id: T4398