[glib/wip/pwithnall/2625-clang-cxx] WIP

[Philip Withnall <pwithnall src gnome org>]

commit fa9223d46829c3decba814dc881a6bd7ed5c8a79
Author: Philip Withnall <pwithnall endlessos org>
Date:   Fri Apr 1 17:03:25 2022 +0100

    WIP
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>

 glib/gatomic.h | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/glib/gatomic.h b/glib/gatomic.h
index 8b2b880c8d..acf6bd610e 100644
--- a/glib/gatomic.h
+++ b/glib/gatomic.h
@@ -196,6 +196,13 @@ G_END_DECLS
     (guint) __atomic_fetch_xor ((atomic), (val), __ATOMIC_SEQ_CST);          \
   }))
 
+#if defined(glib_typeof)
+#pragma message "glib_typeof defined"
+#endif
+#if defined(__cplusplus)
+#pragma message "__cplusplus defined as " ## __cplusplus
+#endif
+
 #if defined(glib_typeof) && defined(__cplusplus) && __cplusplus >= 201103L
 /* This is typesafe because we check we can assign oldval to the type of
  * (*atomic). Unfortunately it can only be done in C++ because gcc/clang warn