Add attributions so printf like functions can have their arguments checked.

runtime/vm/assembler_ia32.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_IA32_H_
 #define VM_ASSEMBLER_IA32_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_ia32.h directly; use assembler.h instead.
 #endif
@@ skipping 562 matching lines @@
   }
 
   // Debugging and bringup support.
   void Stop(const char* message);
   void Unimplemented(const char* message);
   void Untested(const char* message);
   void Unreachable(const char* message);
 
   static void InitializeMemoryWithBreakpoints(uword data, int length);
 
-  void Comment(const char* format, ...);
+  void Comment(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
   const Code::Comments& GetCodeComments() const;
 
   static const char* RegisterName(Register reg);
   static const char* XmmRegisterName(XmmRegister reg);
 
  private:
   AssemblerBuffer buffer_;
   int prolog_offset_;
 
   class CodeComment : public ZoneAllocated {
@@ skipping 63 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_IA32_H_