[gdk-pixbuf/issue-128] Define _XOPEN_SOURCE properly on SunOS

[Emmanuele Bassi <ebassi src gnome org>]

commit d7837e0f7d9ad9a47b5c5f8469e0abece54e01e4
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Apr 2 13:10:59 2020 +0100

    Define _XOPEN_SOURCE properly on SunOS
    
    Fixes: #128

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 411af6ec3..c172b95de 100644
--- a/meson.build
+++ b/meson.build
@@ -8,7 +8,7 @@ project('gdk-pixbuf', 'c',
         ],
         meson_version: '>= 0.48.0')
 
-add_project_arguments([ '-D_POSIX_C_SOURCE=200809L', '-D_DEFAULT_SOURCE', '-D_XOPEN_SOURCE' ], language: 'c')
+add_project_arguments([ '-D_POSIX_C_SOURCE=200809L', '-D_DEFAULT_SOURCE', '-D_XOPEN_SOURCE=500' ], language: 
'c')
 
 cc = meson.get_compiler('c')
 host_system = host_machine.system()