[config] Add HB_NO_LAYOUT_COLLECT_GLYPHS

Part of

src/hb-config.hh

@@ -62,6 +62,7 @@
 #define HB_NO_HINTING
 #define HB_NO_LANGUAGE_PRIVATE_SUBTAG
 #define HB_NO_LAYOUT_FEATURE_PARAMS
+#define HB_NO_LAYOUT_COLLECT_GLYPHS
 #define HB_NO_LAYOUT_UNUSED
 #define HB_NO_MATH
 #define HB_NO_MMAP

src/hb-ot-layout.cc

@@ -1203,6 +1203,7 @@ hb_ot_layout_collect_lookups (hb_face_t      *face,
 }
 
 
+#ifndef HB_NO_LAYOUT_COLLECT_GLYPHS
 /**
  * hb_ot_layout_lookup_collect_glyphs:
  * @face: #hb_face_t to work upon
@@ -1249,6 +1250,7 @@ hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
     }
   }
 }
+#endif
 
 
 /* Variations support */