XXX rework and push upstream

Index: testsuite/reftests/meson.build
--- testsuite/reftests/meson.build.orig
+++ testsuite/reftests/meson.build
@@ -40,11 +40,12 @@ tcdata.set('libexecdir', join_paths(get_option('prefix
 #    configuration : tcdata)
 #endforeach
 
+libexecinfo_dep = cc.find_library('execinfo', required : false)
 gtk_reftest = executable('gtk-reftest',
   sources: 'gtk-reftest.c',
   c_args: common_cflags,
   link_with : [libgtkreftestprivate, libreftest],
-  dependencies : libgtk_dep,
+  dependencies : [libgtk_dep, libexecinfo_dep]
 )
 
 image_compare = executable('image-compare',