[gtk/wip/chergert/quartz4u: 52/55] build: squash various warnings with Clang

[Christian Hergert <chergert src gnome org>]

commit 514b62223da9622c0c42f012c77d55ec130443a3
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jul 17 17:59:09 2020 -0700

    build: squash various warnings with Clang
    
    Otherwise we have really chatty builds that make it difficult to catch
    new issues when compiling.

 meson.build | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/meson.build b/meson.build
index 2d33e6fe34..85656d20c3 100644
--- a/meson.build
+++ b/meson.build
@@ -235,6 +235,8 @@ if cc.get_id() == 'msvc'
 elif cc.get_id() == 'gcc' or cc.get_id() == 'clang'
   test_cflags = [
     '-fno-strict-aliasing',
+    '-Wno-c++11-extensions',
+    '-Wno-missing-include-dirs',
     '-Wno-typedef-redefinition',
     '-Wcast-align',
     '-Wduplicated-branches',