[Interpreter] Add support for for..in.

src/compiler/interpreter-assembler.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/interpreter-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/compiler/graph.h"
@@ skipping 274 matching lines @@
 Node* InterpreterAssembler::LoadConstantPoolEntry(Node* index) {
   Node* constant_pool = LoadObjectField(BytecodeArrayTaggedPointer(),
                                         BytecodeArray::kConstantPoolOffset);
   Node* entry_offset =
       IntPtrAdd(IntPtrConstant(FixedArray::kHeaderSize - kHeapObjectTag),
                 WordShl(index, kPointerSizeLog2));
   return raw_assembler_->Load(kMachAnyTagged, constant_pool, entry_offset);
 }
 
 
+Node* InterpreterAssembler::LoadFixedArrayElement(Node* fixed_array,
+                                                  int index) {
+  Node* entry_offset =
+      IntPtrAdd(IntPtrConstant(FixedArray::kHeaderSize - kHeapObjectTag),
+                WordShl(Int32Constant(index), kPointerSizeLog2));
+  return raw_assembler_->Load(kMachAnyTagged, fixed_array, entry_offset);
+}
+
+
 Node* InterpreterAssembler::LoadObjectField(Node* object, int offset) {
   return raw_assembler_->Load(kMachAnyTagged, object,
                               IntPtrConstant(offset - kHeapObjectTag));
 }
 
 
 Node* InterpreterAssembler::LoadContextSlot(Node* context, int slot_index) {
   return raw_assembler_->Load(kMachAnyTagged, context,
                               IntPtrConstant(Context::SlotOffset(slot_index)));
 }
@@ skipping 324 matching lines @@
   return raw_assembler_->schedule();
 }
 
 
 Zone* InterpreterAssembler::zone() { return raw_assembler_->zone(); }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8