Remove more feature in product mode

runtime/vm/disassembler_mips.cc

 // Copyright (c) 2013, 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.
 
 #include "vm/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 #include "platform/assert.h"
 
 namespace dart {
 
+#ifndef PRODUCT
+
 class MIPSDecoder : public ValueObject {
  public:
   MIPSDecoder(char* buffer, size_t buffer_size)
       : buffer_(buffer),
         buffer_size_(buffer_size),
         buffer_pos_(0) {
     buffer_[buffer_pos_] = '\0';
   }
 
   ~MIPSDecoder() {}
@@ skipping 744 matching lines @@
                                      int* out_instr_len, uword pc) {
   MIPSDecoder decoder(human_buffer, human_size);
   Instr* instr = Instr::At(pc);
   decoder.InstructionDecode(instr);
   OS::SNPrint(hex_buffer, hex_size, "%08x", instr->InstructionBits());
   if (out_instr_len) {
     *out_instr_len = Instr::kInstrSize;
   }
 }
 
+#endif  // !PRODUCT
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS