Fix build.

runtime/vm/disassembler_x64.cc

 // 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.
 
 #include "vm/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_X64)
 #include "platform/utils.h"
 #include "vm/allocation.h"
@@ skipping 1847 matching lines @@
 
   ASSERT(buffer_[buffer_pos_] == '\0');
 
   int instr_len = data - reinterpret_cast<uint8_t*>(pc);
   ASSERT(instr_len > 0);  // Ensure progress.
 
   return instr_len;
 }
 
 
-int Disassembler::DecodeInstruction(char* hex_buffer, intptr_t hex_size,
+bool Disassembler::DecodeInstruction(char* hex_buffer, intptr_t hex_size,
                                     char* human_buffer, intptr_t human_size,
                                     int* out_instr_len, uword pc) {
   ASSERT(hex_size > 0);
   ASSERT(human_size > 0);
   DisassemblerX64 decoder(human_buffer, human_size);
   int instruction_length = decoder.InstructionDecode(pc);
   uint8_t* pc_ptr = reinterpret_cast<uint8_t*>(pc);
   int hex_index = 0;
   int remaining_size = hex_size - hex_index;
   for (int i = 0; (i < instruction_length) && (remaining_size > 2); ++i) {
@@ skipping 40 matching lines @@
                                   pc);
     pc += instruction_length;
   }
 
   return true;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64