[Interpreter] Enable assignments in expressions.

src/interpreter/interpreter.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/interpreter/interpreter.h"
 
 #include "src/code-factory.h"
 #include "src/compiler.h"
 #include "src/compiler/interpreter-assembler.h"
 #include "src/factory.h"
@@ skipping 182 matching lines @@
 //
 // Store accumulator to register <dst>.
 void Interpreter::DoStar(compiler::InterpreterAssembler* assembler) {
   Node* reg_index = __ BytecodeOperandReg(0);
   Node* accumulator = __ GetAccumulator();
   __ StoreRegister(accumulator, reg_index);
   __ Dispatch();
 }
 
 
+// Mov <src> <dst>
+//
+// Stores the value of register <src> to register <dst>.
+void Interpreter::DoMov(compiler::InterpreterAssembler* assembler) {
+  Node* src_index = __ BytecodeOperandReg(0);
+  Node* src_value = __ LoadRegister(src_index);
+  Node* dst_index = __ BytecodeOperandReg(1);
+  __ StoreRegister(src_value, dst_index);
+  __ Dispatch();
+}
+
+
 void Interpreter::DoLoadGlobal(Callable ic,
                                compiler::InterpreterAssembler* assembler) {
   // Get the global object.
   Node* context = __ GetContext();
   Node* global = __ LoadContextSlot(context, Context::GLOBAL_OBJECT_INDEX);
 
   // Load the global via the LoadIC.
   Node* code_target = __ HeapConstant(ic.code());
   Node* constant_index = __ BytecodeOperandIdx(0);
   Node* name = __ LoadConstantPoolEntry(constant_index);
   Node* raw_slot = __ BytecodeOperandIdx(1);
   Node* smi_slot = __ SmiTag(raw_slot);
   Node* type_feedback_vector = __ LoadTypeFeedbackVector();
   Node* result = __ CallIC(ic.descriptor(), code_target, global, name, smi_slot,
                            type_feedback_vector);
   __ SetAccumulator(result);
-
   __ Dispatch();
 }
 
 
 // LdaGlobalSloppy <name_index> <slot>
 //
 // Load the global with name in constant pool entry <name_index> into the
 // accumulator using FeedBackVector slot <slot> in sloppy mode.
 void Interpreter::DoLdaGlobalSloppy(compiler::InterpreterAssembler* assembler) {
   Callable ic = CodeFactory::LoadICInOptimizedCode(isolate_, NOT_INSIDE_TYPEOF,
@@ skipping 1235 matching lines @@
   Node* cache_length = __ LoadFixedArrayElement(for_in_state, 3);
   Node* result = __ CallRuntime(Runtime::kForInDone, index, cache_length);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8