[babl/wip/msvc] babl/babl-internal.c: Include process.h on Windows

[Chun-wei Fan <fanchunwei src gnome org>]

commit 7e8e084ac77a6149345736fca2963c44cdb5b545
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Jan 20 16:44:55 2020 +0800

    babl/babl-internal.c: Include process.h on Windows
    
    system() is defined in process.h on Windows, as unistd.h is not universally
    available

 babl/babl-internal.c | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/babl/babl-internal.c b/babl/babl-internal.c
index f7939a1b3..e5afa05d0 100644
--- a/babl/babl-internal.c
+++ b/babl/babl-internal.c
@@ -58,7 +58,12 @@ babl_class_name (BablClassType klass)
 int babl_hmpf_on_name_lookups = 0;
 
 #include <sys/types.h>
+
+#ifdef _WIN32
+#include <process.h>
+#else
 #include <unistd.h>
+#endif
 
 int
 babl_backtrack (void)