[gtk/testsuite-asserts: 11/13] build: Don't append multiple flags as a string

[Matthias Clasen <matthiasc src gnome org>]

commit a871a1bdb5df8cd221a10508c162e6def5c55a37
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Apr 12 11:29:24 2021 +0100

    build: Don't append multiple flags as a string
    
    The gtk_debug_cflags variable is an array, with each argument stored in
    a separate string; if we add multiple arguments inside the same string
    we break the escaping rules.
    
    Fixes: #3864

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 26cda67aba..7223431ddf 100644
--- a/meson.build
+++ b/meson.build
@@ -66,7 +66,7 @@ if debug
     gtk_debug_cflags += '-DG_ENABLE_CONSISTENCY_CHECKS'
   endif
 elif optimization in ['2', '3', 's']
-  gtk_debug_cflags += '-DG_DISABLE_CAST_CHECKS -DG_DISABLE_ASSERT'
+  gtk_debug_cflags += ['-DG_DISABLE_CAST_CHECKS', '-DG_DISABLE_ASSERT']
 endif
 
 add_project_arguments(gtk_debug_cflags, language: 'c')