Add DISALLOW_COPY_AND_ASSIGN to subclasses of ValueObject and make ValueObject copyable.

runtime/vm/assembler_x64.h

Index: runtime/vm/assembler_x64.h
===================================================================
--- runtime/vm/assembler_x64.h	(revision 18957)
+++ runtime/vm/assembler_x64.h	(working copy)
@@ -22,8 +22,6 @@
  public:
   explicit Immediate(int64_t value) : value_(value) { }
 
-  Immediate(const Immediate& other) : ValueObject(), value_(other.value_) { }
-
   int64_t value() const { return value_; }
 
   bool is_int8() const { return Utils::IsInt(8, value_); }
@@ -34,9 +32,7 @@
  private:
   const int64_t value_;
 
-  // TODO(5411081): Add DISALLOW_COPY_AND_ASSIGN(Immediate) once the mac
-  // build issue is resolved.
-  // And remove the unnecessary copy constructor.
+  DISALLOW_COPY_AND_ASSIGN(Immediate);
 };
 
 
@@ -79,20 +75,9 @@
     return bit_copy<int32_t>(encoding_[length_ - 4]);
   }
 
-  Operand(const Operand& other)
-      : ValueObject(), length_(other.length_), rex_(other.rex_) {
-    memmove(&encoding_[0], &other.encoding_[0], other.length_);
-  }
-
-  Operand& operator=(const Operand& other) {
-    length_ = other.length_;
-    rex_ = other.rex_;
-    memmove(&encoding_[0], &other.encoding_[0], other.length_);
-    return *this;
-  }
-
  protected:
-  Operand() : length_(0), rex_(REX_NONE) { }  // Needed by subclass Address.
+  // Needed by subclass Address.
+  Operand() : length_(0), rex_(REX_NONE), encoding_() { }
 
   void SetModRM(int mod, Register rm) {
     ASSERT((mod & ~3) == 0);
@@ -196,13 +181,6 @@
       SetDisp32(disp);
     }
   }
-
-  Address(const Address& other) : Operand(other) { }
-
-  Address& operator=(const Address& other) {
-    Operand::operator=(other);
-    return *this;
-  }
 };
 
 
@@ -213,13 +191,6 @@
 
   FieldAddress(Register base, Register index, ScaleFactor scale, int32_t disp)
       : Address(base, index, scale, disp - kHeapObjectTag) { }
-
-  FieldAddress(const FieldAddress& other) : Address(other) { }
-
-  FieldAddress& operator=(const FieldAddress& other) {
-    Address::operator=(other);
-    return *this;
-  }
 };
 
 
@@ -770,7 +741,6 @@
 
   void StoreIntoObjectFilter(Register object, Register value, Label* no_update);
 
-  DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };