[gtk+] build: Warn about ignored qualifiers

[Benjamin Otte <otte src gnome org>]

commit 3a8f2ae64f1f9a607c27511a7d6042cc995d14d4
Author: Benjamin Otte <otte redhat com>
Date:   Mon Oct 23 16:28:38 2017 +0200

    build: Warn about ignored qualifiers
    
    https://bugzilla.gnome.org/show_bug.cgi?id=789351

 meson.build |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/meson.build b/meson.build
index b732bd2..0084685 100644
--- a/meson.build
+++ b/meson.build
@@ -236,6 +236,7 @@ elif cc.get_id() == 'gcc' or cc.get_id() == 'clang'
     '-Wlogical-op',
     '-Wswitch-default',
     '-Wswitch-enum',
+    '-Wignored-qualifiers',
     '-Werror=redundant-decls',
     '-Werror=implicit',
     '-Werror=nonnull',