Add DISALLOW_COPY_AND_ASSIGN to subclasses of ValueObject and make ValueObject copyable.

runtime/vm/assembler_mips.h

Index: runtime/vm/assembler_mips.h
===================================================================
--- runtime/vm/assembler_mips.h	(revision 18957)
+++ runtime/vm/assembler_mips.h	(working copy)
@@ -15,16 +15,6 @@
 namespace dart {
 
 class Operand : public ValueObject {
- public:
-  Operand(const Operand& other) : ValueObject() {
-    UNIMPLEMENTED();
-  }
-
-  Operand& operator=(const Operand& other) {
-    UNIMPLEMENTED();
-    return *this;
-  }
-
  protected:
   Operand() { }  // Needed by subclass Address.
 };
@@ -35,13 +25,6 @@
   Address(Register base, int32_t disp) {
     UNIMPLEMENTED();
   }
-
-  Address(const Address& other) : Operand(other) { }
-
-  Address& operator=(const Address& other) {
-    Operand::operator=(other);
-    return *this;
-  }
 };
 
 
@@ -49,13 +32,6 @@
  public:
   FieldAddress(Register base, int32_t disp)
       : Address(base, disp - kHeapObjectTag) { }
-
-  FieldAddress(const FieldAddress& other) : Address(other) { }
-
-  FieldAddress& operator=(const FieldAddress& other) {
-    Address::operator=(other);
-    return *this;
-  }
 };
 
 
@@ -198,7 +174,6 @@
 
   GrowableArray<CodeComment*> comments_;
 
-  DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };