Reland of Type Feedback Vector lives in the closure

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index f6f3287bfbe388c3782756d1ca99b1057e42310f..4cf6cda51ccf3964f8a25289659d9b55bf41e1c9 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -3390,11 +3390,19 @@ LiteralsArray* LiteralsArray::cast(Object* object) {
 
 
 TypeFeedbackVector* LiteralsArray::feedback_vector() const {
+  if (length() == 0) {
+    return TypeFeedbackVector::cast(
+        const_cast<FixedArray*>(FixedArray::cast(this)));
+  }
   return TypeFeedbackVector::cast(get(kVectorIndex));
 }
 
 
 void LiteralsArray::set_feedback_vector(TypeFeedbackVector* vector) {
+  if (length() <= kVectorIndex) {
+    DCHECK(vector->length() == 0);
+    return;
+  }
   set(kVectorIndex, vector);
 }
 
@@ -3408,6 +3416,9 @@ void LiteralsArray::set_literal(int literal_index, Object* literal) {
   set(kFirstLiteralIndex + literal_index, literal);
 }
 
+void LiteralsArray::set_literal_undefined(int literal_index) {
+  set_undefined(kFirstLiteralIndex + literal_index);
+}
 
 int LiteralsArray::literals_count() const {
   return length() - kFirstLiteralIndex;
@@ -5621,8 +5632,8 @@ ACCESSORS(SharedFunctionInfo, name, Object, kNameOffset)
 ACCESSORS(SharedFunctionInfo, optimized_code_map, FixedArray,
           kOptimizedCodeMapOffset)
 ACCESSORS(SharedFunctionInfo, construct_stub, Code, kConstructStubOffset)
-ACCESSORS(SharedFunctionInfo, feedback_vector, TypeFeedbackVector,
-          kFeedbackVectorOffset)
+ACCESSORS(SharedFunctionInfo, feedback_metadata, TypeFeedbackMetadata,
+          kFeedbackMetadataOffset)
 #if TRACE_MAPS
 SMI_ACCESSORS(SharedFunctionInfo, unique_id, kUniqueIdOffset)
 #endif
@@ -5804,6 +5815,26 @@ void SharedFunctionInfo::set_kind(FunctionKind kind) {
   set_compiler_hints(hints);
 }
 
+// static
+int SharedFunctionInfo::OffsetToPreviousContext() {
+  return FixedArray::kHeaderSize +
+         kPointerSize * (kContextOffset - kEntryLength);
+}
+
+int SharedFunctionInfo::OffsetToPreviousCachedCode() {
+  return FixedArray::kHeaderSize +
+         kPointerSize * (kCachedCodeOffset - kEntryLength);
+}
+
+int SharedFunctionInfo::OffsetToPreviousLiterals() {
+  return FixedArray::kHeaderSize +
+         kPointerSize * (kLiteralsOffset - kEntryLength);
+}
+
+int SharedFunctionInfo::OffsetToPreviousOsrAstId() {
+  return FixedArray::kHeaderSize +
+         kPointerSize * (kOsrAstIdOffset - kEntryLength);
+}
 
 BOOL_ACCESSORS(SharedFunctionInfo, compiler_hints, needs_home_object,
                kNeedsHomeObject)
@@ -6255,11 +6286,12 @@ bool JSFunction::is_compiled() {
          code() != builtins->builtin(Builtins::kCompileOptimizedConcurrent);
 }
 
-
-int JSFunction::NumberOfLiterals() {
-  return literals()->length();
+TypeFeedbackVector* JSFunction::feedback_vector() {
+  LiteralsArray* array = literals();
+  return array->feedback_vector();
 }
 
+int JSFunction::NumberOfLiterals() { return literals()->literals_count(); }
 
 ACCESSORS(JSProxy, target, JSReceiver, kTargetOffset)
 ACCESSORS(JSProxy, handler, Object, kHandlerOffset)