Introduce LiteralsArray to hide it's implementation.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index c3a3b1570ffac982490b184681f153691e8e021b..c1d430818c724956a3ba3ab119686a1e351a00e7 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -1324,7 +1324,8 @@ Handle<JSFunction> Factory::NewFunctionFromSharedFunctionInfo(
 
   } else if (!info->bound()) {
     int number_of_literals = info->num_literals();
-    Handle<FixedArray> literals = NewFixedArray(number_of_literals, pretenure);
+    Handle<LiteralsArray> literals = NewLiteralsArray(
+        handle(info->feedback_vector()), number_of_literals, pretenure);
     result->set_literals(*literals);
     // Cache context-specific literals.
     if (FLAG_cache_optimized_code) {
@@ -2086,6 +2087,17 @@ Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(
 }
 
 
+Handle<LiteralsArray> Factory::NewLiteralsArray(
+    Handle<TypeFeedbackVector> vector, int number_of_literals,
+    PretenureFlag pretenure) {
+  Handle<FixedArray> literals =
+      NewFixedArray(LiteralsArray::SizeFor(number_of_literals), pretenure);

[Igor Sheludko, 2015/09/28 16:35:27]

I'm afraid that here we will actually call FixedArray::SizeFor() which doesn't
know about additional slots. Maybe we should add LiteralsArray:SizeFor() and
implement OffsetOfLiteralAt() in terms of SizeFor().

[mvstanton, 2015/09/29 08:25:13]

Okay, I see I was using SizeFor incorrectly. It is a method that returns the
number of bytes needed for the whole FixedArray, whereas creating the array here
we need the number of elements. So how about if I move the actual creation
inside of LiteralsArray, and the factory method is just here as the canonical
way to access it. Because, why should factory.cc know that a LiteralsArray is a
fixed array of size length+1?

+  Handle<LiteralsArray> casted_literals = Handle<LiteralsArray>::cast(literals);
+  casted_literals->set_feedback_vector(*vector);
+  return casted_literals;
+}
+
+
 Handle<JSMessageObject> Factory::NewJSMessageObject(
     MessageTemplate::Template message, Handle<Object> argument,
     int start_position, int end_position, Handle<Object> script,