Yet another attempt at gcc-14 lstat/realpath (#9703 PR #893)

See also 4b8b5ac and realpath(3)

```
realpath():
   _XOPEN_SOURCE >= 500
       || /* Glibc since 2.19: */ _DEFAULT_SOURCE
       || /* Glibc versions <= 2.19: */ _BSD_SOURCE
```

Author: x42

libs/aaf/wscript

@@ -60,7 +60,7 @@ def build(bld):
     #obj.uselib          = 'GLIB'
     obj.vnum             = LIBAAF_LIB_VERSION
     obj.install_path     = bld.env['LIBDIR']
-    obj.defines         += [ 'PACKAGE="' + I18N_PACKAGE + '"', '_POSIX_C_SOURCE=200809L' ]
+    obj.defines         += [ 'PACKAGE="' + I18N_PACKAGE + '"', '_POSIX_C_SOURCE=200809L', '_XOPEN_SOURCE=500' ]
 
 def shutdown():
     autowaf.shutdown()