Use a breakpoint instruction for a stop message on arm instead of

runtime/vm/assembler_arm64.cc

 // 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.
 
 #include "vm/globals.h"  // NOLINT
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 203 matching lines @@
 
 void Assembler::Stop(const char* message) {
   if (FLAG_print_stop_message) {
     UNIMPLEMENTED();
   }
   Label stop;
   b(&stop);
   Emit(Utils::Low32Bits(reinterpret_cast<int64_t>(message)));
   Emit(Utils::High32Bits(reinterpret_cast<int64_t>(message)));
   Bind(&stop);
-  hlt(Instr::kStopMessageCode);
+  brk(Instr::kStopMessageCode);
 }
 
 
 static int CountLeadingZeros(uint64_t value, int width) {
   ASSERT((width == 32) || (width == 64));
   if (value == 0) {
     return width;
   }
   int count = 0;
   do {
@@ skipping 1251 matching lines @@
     add(base, array, Operand(index, LSL, shift));
   }
   const OperandSize size = Address::OperandSizeFor(cid);
   ASSERT(Address::CanHoldOffset(offset, Address::Offset, size));
   return Address(base, offset, Address::Offset, size);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64