Merge WebKit at r59636: Update v8 to r4660.

Will build and run with current webkit.

Change-Id: I57bae621fd894da363ba84e1757ad09eb7c502b9
diff --git a/src/objects-inl.h b/src/objects-inl.h
index ae7d2c2..ad15104 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -2530,7 +2530,13 @@
 
 
 bool SharedFunctionInfo::HasCustomCallGenerator() {
-  return function_data()->IsProxy();
+  return function_data()->IsSmi();
+}
+
+
+int SharedFunctionInfo::custom_call_generator_id() {
+  ASSERT(HasCustomCallGenerator());
+  return Smi::cast(function_data())->value();
 }