Uses SNPRINT macro where possible. Otherwise uses #define for format.

runtime/vm/assembler_arm64.h

 // Copyright (c) 2014, 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_ARM64_H_
 #define VM_ASSEMBLER_ARM64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm64.h directly; use assembler.h instead.
 #endif
@@ skipping 480 matching lines @@
     ASSERT(buffer_.Size() == 0);
     use_far_branches_ = b;
   }
 
   void FinalizeInstructions(const MemoryRegion& region) {
     buffer_.FinalizeInstructions(region);
   }
 
   // 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, intptr_t length);
 
   void Comment(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
   static bool EmittingComments();
 
   const Code::Comments& GetCodeComments() const;
 
   static const char* RegisterName(Register reg);
 
@@ skipping 1409 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM64_H_