V8 support for cached accessors.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 0f77fdf2225b88ede69682728803575a4402f78f..d014cf6a1859880c1ec568b8ec194e59c3adb706 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -11432,6 +11432,8 @@ class FunctionTemplateInfo: public TemplateInfo {
   DECL_BOOLEAN_ACCESSORS(do_not_cache)
   DECL_BOOLEAN_ACCESSORS(accept_any_receiver)
 
+  DECL_ACCESSORS(cache_property, Object)
+
   DECLARE_CAST(FunctionTemplateInfo)
 
   // Dispatched behavior.
@@ -11458,7 +11460,8 @@ class FunctionTemplateInfo: public TemplateInfo {
       kAccessCheckInfoOffset + kPointerSize;
   static const int kFlagOffset = kSharedFunctionInfoOffset + kPointerSize;
   static const int kLengthOffset = kFlagOffset + kPointerSize;
-  static const int kSize = kLengthOffset + kPointerSize;
+  static const int kCachePropertyOffset = kLengthOffset + kPointerSize;
+  static const int kSize = kCachePropertyOffset + kPointerSize;
 
   static Handle<SharedFunctionInfo> GetOrCreateSharedFunctionInfo(
       Isolate* isolate, Handle<FunctionTemplateInfo> info);
@@ -11469,6 +11472,10 @@ class FunctionTemplateInfo: public TemplateInfo {
   bool IsTemplateFor(Map* map);
   inline bool instantiated();
 
+  // Helper function for cached accessors.
+  static MaybeHandle<Name> TryGetCachePropertyName(Isolate* isolate,
+                                                   Handle<Object> getter);
+
  private:
   // Bit position in the flag, from least significant bit position.
   static const int kHiddenPrototypeBit   = 0;