Issue #12736: dialogs have odd kerning (related to harfbuzz).

Thanks to René de Hesselle for figuring out that the issue happens when
Harfbuzz is not built with libgraphite2.
As far as we know, this is a macOS-only issue.

The issue has already been fixed in our macOS packages, but just to make
sure this doesn't reappear, let's add a configure test.

Note: when we'll bump to using meson >= 1.5.0, we can use option
`required: platform_osx` of cc.run().

meson.build

@@ -494,6 +494,30 @@ add_project_arguments('-DGDK_VERSION_MAX_ALLOWED=' + gtk_min_macro, language: 'c
 
 harfbuzz_minver   = '2.8.2'
 harfbuzz          = dependency('harfbuzz',           version: '>='+harfbuzz_minver)
+
+if platform_osx and \
+   cc.run('''
+          #include <string.h>
+          #include <hb.h>
+
+          int
+          main (int argc, char **argv)
+          {
+            const char **shapers = hb_shape_list_shapers ();
+
+            for (int i = 0; shapers[i] != NULL; i++)
+              if (strcmp (shapers[i], "graphite2") == 0)
+                return 0;
+
+            return 1;
+          }
+          ''',
+          name: 'harfbuzz is built with graphite2 shaper',
+          dependencies: harfbuzz).returncode() != 0
+  error('harfbuzz must be built with graphite2 shaper on macOS.')
+endif
+
+
 json_glib_minver  = '1.2.6'
 json_glib         = dependency('json-glib-1.0',      version: '>='+json_glib_minver)
 lcms_minver       = '2.8'