[glib/gconstrutor-h-stdlib-h-msvc] glib/gconstructor.h: Include stdlib.h for MSVC builds

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

commit d4238b9a1976e5a7ff259d7f61c5f22e6f153ba1
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Apr 24 13:27:22 2019 +0800

    glib/gconstructor.h: Include stdlib.h for MSVC builds
    
    This is in case the compiler complains that we don't have the prototypes
    for atexit(), and it doesn't hurt to include that file here.

 glib/gconstructor.h | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/glib/gconstructor.h b/glib/gconstructor.h
index dccb0314c..603c2dde6 100644
--- a/glib/gconstructor.h
+++ b/glib/gconstructor.h
@@ -28,6 +28,8 @@
 #elif defined (_MSC_VER) && (_MSC_VER >= 1500)
 /* Visual studio 2008 and later has _Pragma */
 
+#include <stdlib.h>
+
 #define G_HAS_CONSTRUCTORS 1
 
 /* We do some weird things to avoid the constructors being optimized