Rename VOID and void_t to have HarfBuzz prefix

Fixes build on Windows.  Ouch!

src/hb-ot-layout-gsubgpos-private.hh

@@ -49,7 +49,7 @@ namespace OT {
 #endif
 
 #define TRACE_CLOSURE(this) \
-	hb_auto_trace_t<HB_DEBUG_CLOSURE, void_t> trace \
+	hb_auto_trace_t<HB_DEBUG_CLOSURE, hb_void_t> trace \
 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
 	 "");
 
@@ -57,11 +57,11 @@ struct hb_closure_context_t
 {
   inline const char *get_name (void) { return "CLOSURE"; }
   static const unsigned int max_debug_depth = HB_DEBUG_CLOSURE;
-  typedef void_t return_t;
+  typedef hb_void_t return_t;
   typedef return_t (*recurse_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
   template <typename T>
-  inline return_t process (const T &obj) { obj.closure (this); return VOID; }
-  static return_t default_return_value (void) { return VOID; }
+  inline return_t process (const T &obj) { obj.closure (this); return HB_VOID; }
+  static return_t default_return_value (void) { return HB_VOID; }
   bool stop_sublookup_iteration (const return_t r) const { return false; }
   return_t recurse (unsigned int lookup_index)
   {
@@ -71,7 +71,7 @@ struct hb_closure_context_t
     nesting_level_left--;
     recurse_func (this, lookup_index);
     nesting_level_left++;
-    return VOID;
+    return HB_VOID;
   }
 
   hb_face_t *face;
@@ -137,7 +137,7 @@ struct hb_would_apply_context_t
 #endif
 
 #define TRACE_COLLECT_GLYPHS(this) \
-	hb_auto_trace_t<HB_DEBUG_COLLECT_GLYPHS, void_t> trace \
+	hb_auto_trace_t<HB_DEBUG_COLLECT_GLYPHS, hb_void_t> trace \
 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
 	 "");
 
@@ -145,11 +145,11 @@ struct hb_collect_glyphs_context_t
 {
   inline const char *get_name (void) { return "COLLECT_GLYPHS"; }
   static const unsigned int max_debug_depth = HB_DEBUG_COLLECT_GLYPHS;
-  typedef void_t return_t;
+  typedef hb_void_t return_t;
   typedef return_t (*recurse_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
   template <typename T>
-  inline return_t process (const T &obj) { obj.collect_glyphs (this); return VOID; }
-  static return_t default_return_value (void) { return VOID; }
+  inline return_t process (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
+  static return_t default_return_value (void) { return HB_VOID; }
   bool stop_sublookup_iteration (const return_t r) const { return false; }
   return_t recurse (unsigned int lookup_index)
   {
@@ -161,7 +161,7 @@ struct hb_collect_glyphs_context_t
      * glyphs in the recursion.  If output is not requested, we can go home now. */
 
     if (output == hb_set_get_empty ())
-      return VOID;
+      return HB_VOID;
 
     hb_set_t *old_before = before;
     hb_set_t *old_input  = input;
@@ -176,7 +176,7 @@ struct hb_collect_glyphs_context_t
     input  = old_input;
     after  = old_after;
 
-    return VOID;
+    return HB_VOID;
   }
 
   hb_face_t *face;

src/hb-private.hh

@@ -63,9 +63,9 @@
 
 
 /* Void! */
-struct _void_t;
-typedef const _void_t &void_t;
-#define VOID (* (const _void_t *) NULL)
+struct _hb_void_t;
+typedef const _hb_void_t &hb_void_t;
+#define HB_VOID (* (const _hb_void_t *) NULL)
 
 
 /* Basics */
@@ -679,8 +679,8 @@ struct hb_printer_t<bool> {
 };
 
 template <>
-struct hb_printer_t<void_t> {
-  const char *print (void_t v) { return ""; }
+struct hb_printer_t<hb_void_t> {
+  const char *print (hb_void_t v) { return ""; }
 };
 
 
@@ -696,7 +696,7 @@ static inline void _hb_warn_no_return (bool returned)
   }
 }
 template <>
-inline void _hb_warn_no_return<void_t> (bool returned)
+inline void _hb_warn_no_return<hb_void_t> (bool returned)
 {}
 
 template <int max_level, typename ret_t>