[Interpreter] Enable assignments in expressions.

src/interpreter/bytecodes.h

Index: src/interpreter/bytecodes.h
diff --git a/src/interpreter/bytecodes.h b/src/interpreter/bytecodes.h
index 96e4c35d6fdad1e60e20bdc501847719f4e0b9fc..5bafb2eb22becc7a0580151a3bda39c7200efd3e 100644
--- a/src/interpreter/bytecodes.h
+++ b/src/interpreter/bytecodes.h
@@ -64,6 +64,9 @@ namespace interpreter {
   V(Ldar, OperandType::kReg8)                                                  \
   V(Star, OperandType::kReg8)                                                  \
                                                                                \
+  /* Register-register transfers */                                            \
+  V(Mov, OperandType::kReg8, OperandType::kReg8)                               \
+                                                                               \
   /* LoadIC operations */                                                      \
   V(LoadICSloppy, OperandType::kReg8, OperandType::kIdx8, OperandType::kIdx8)  \
   V(LoadICStrict, OperandType::kReg8, OperandType::kIdx8, OperandType::kIdx8)  \
@@ -260,9 +263,7 @@ class Register {
   bool operator!=(const Register& other) const {
     return index() != other.index();
   }
-  bool operator<(const Register& other) const {
-    return index() < other.index();
-  }
+  bool operator<(const Register& other) const { return index_ < other.index_; }

[rmcilroy, 2015/11/03 14:17:52]

Could you check why this is needed?

[oth, 2015/11/04 10:03:37]

Restored. No longer needed, not sure where in the history this was needed.

   bool operator<=(const Register& other) const {
     return index() <= other.index();
   }
@@ -270,9 +271,6 @@ class Register {
  private:
   static const int kIllegalIndex = kMaxInt;
 
-  void* operator new(size_t size);
-  void operator delete(void* p);

[rmcilroy, 2015/11/03 14:17:52]

We could keep this by using index() in the containers instead, but I'll leave it
to you.

[oth, 2015/11/04 10:03:37]

Put these back and went with index() in the containers.

-
   int index_;
 };