ARM64: Fix disassembly of branch targets.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/225743004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20543 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm64/disasm-arm64.cc

@@ -1632,10 +1632,9 @@ int Disassembler::SubstituteBranchTargetField(Instruction* instr,
   offset <<= kInstructionSizeLog2;
   char sign = '+';
   if (offset < 0) {
-    offset = -offset;
     sign = '-';
   }
-  AppendToOutput("#%c0x%" PRIx64 " (addr %p)", sign, offset,
+  AppendToOutput("#%c0x%" PRIx64 " (addr %p)", sign, Abs(offset),
                  instr->InstructionAtOffset(offset), Instruction::NO_CHECK);
   return 8;
 }