* configure.ac (AC_FUNC_FORK): No use.
* src/gpg-error.h.in (@define:gpgrt_process_t@): New.
(@define:pid_t@): Remove.
(gpgrt_spawn_process, gpgrt_spawn_process_fd): Use gpgrt_process_t.
(gpgrt_wait_process, gpgrt_wait_processes): Likewise.
(gpgrt_kill_process, gpgrt_release_process): Likewise.
* src/gpgrt-int.h (_gpgrt_spawn_process): Likewise.
(_gpgrt_spawn_process_fd): Likewise.
(_gpgrt_wait_process, _gpgrt_wait_processes): Likewise.
(_gpgrt_kill_process, _gpgrt_release_process): Likewise.
* src/mkheader.c (write_special): Handle @define:gpgrt_process_t@.
Remove handling of @define:pid_t@.
* src/spawn-posix.c (_gpgrt_spawn_process): Use gpgrt_process_t.
(_gpgrt_spawn_process_fd): Likewise.
(_gpgrt_wait_process, _gpgrt_wait_processes): Likewise.
(_gpgrt_kill_process, _gpgrt_release_process): Likewise.
* src/spawn-w32.c (_gpgrt_spawn_process): Use gpgrt_process_t.
(_gpgrt_spawn_process_fd): Likewise.
(_gpgrt_wait_process, _gpgrt_wait_processes): Likewise.
(_gpgrt_kill_process, _gpgrt_release_process): Likewise.