[libglnx/wip/smcv/easy-constants: 1/2] backports: Backport G_SPAWN_DEFAULT

[Simon McVittie <smcv src gnome org>]

commit 7d599d7de2e2d7a36b0f9d38533c76bc863a5d10
Author: Simon McVittie <smcv collabora com>
Date:   Wed Jul 27 15:42:43 2022 +0100

    backports: Backport G_SPAWN_DEFAULT
    
    This makes the absence of flags a bit clearer to write.
    
    Signed-off-by: Simon McVittie <smcv collabora com>

 glnx-backports.h | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/glnx-backports.h b/glnx-backports.h
index 0c5fabe..3de9370 100644
--- a/glnx-backports.h
+++ b/glnx-backports.h
@@ -64,6 +64,10 @@ gboolean              glnx_set_object  (GObject **object_ptr,
 
 #endif /* !GLIB_CHECK_VERSION(2, 44, 0) */
 
+#if !GLIB_CHECK_VERSION(2, 38, 0)
+#define G_SPAWN_DEFAULT ((GSpawnFlags) 0)
+#endif
+
 #ifndef g_assert_nonnull
 #define g_assert_nonnull(x) g_assert (x != NULL)
 #endif