[config] Add HB_NO_OT_LAYOUT

Part of https://github.com/harfbuzz/harfbuzz/issues/1652

src/hb-config.hh

@@ -123,6 +123,7 @@
 
 #ifdef HB_NO_OT
 #define HB_NO_OT_FONT
+#define HB_NO_OT_LAYOUT
 #define HB_NO_OT_SHAPE
 #endif
 

src/hb-ot-layout.cc

@@ -28,6 +28,10 @@
  * Google Author(s): Behdad Esfahbod
  */
 
+#include "hb.hh"
+
+#ifndef HB_NO_OT_LAYOUT
+
 #include "hb-open-type.hh"
 #include "hb-ot-layout.hh"
 #include "hb-ot-face.hh"
@@ -2000,3 +2004,6 @@ hb_ot_layout_get_baseline (hb_font_t               *font,
 			   hb_position_t           *coord        /* OUT.  May be NULL. */);
 
 #endif
+
+
+#endif

src/hb-ot-map.cc

@@ -26,6 +26,10 @@
  * Google Author(s): Behdad Esfahbod
  */
 
+#include "hb.hh"
+
+#ifndef HB_NO_OT_SHAPE
+
 #include "hb-ot-map.hh"
 #include "hb-ot-shape.hh"
 #include "hb-ot-layout.hh"
@@ -332,3 +336,6 @@ hb_ot_map_builder_t::compile (hb_ot_map_t                  &m,
     }
   }
 }
+
+
+#endif