Add support for debug break in Dart source.

runtime/vm/simulator_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 <setjmp.h>  // NOLINT
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_MIPS)
 
@@ skipping 1199 matching lines @@
   ASSERT(instr->OpcodeField() == SPECIAL);
   ASSERT(instr->FunctionField() == BREAK);
   if (instr->BreakCodeField() == Instr::kStopMessageCode) {
     SimulatorDebugger dbg(this);
     const char* message = *reinterpret_cast<const char**>(
         reinterpret_cast<intptr_t>(instr) - Instr::kInstrSize);
     set_pc(get_pc() + Instr::kInstrSize);
     dbg.Stop(instr, message);
     // Adjust for extra pc increment.
     set_pc(get_pc() - Instr::kInstrSize);
-  } else if (instr->BreakCodeField() == Instr::kSimulatorMessageCode) {
-    const char* message = *reinterpret_cast<const char**>(
-        reinterpret_cast<intptr_t>(instr) - Instr::kInstrSize);
-    if (IsTracingExecution()) {
-      OS::Print("Message: %s\n", message);
-    }
   } else if (instr->BreakCodeField() == Instr::kSimulatorRedirectCode) {
     SimulatorSetjmpBuffer buffer(this);
 
     if (!setjmp(buffer.buffer_)) {
       int32_t saved_ra = get_register(RA);
       Redirection* redirection = Redirection::FromBreakInstruction(instr);
       uword external = redirection->external_function();
       if (IsTracingExecution()) {
         OS::Print("Call to host function at 0x%" Pd "\n", external);
       }
@@ skipping 1251 matching lines @@
   set_register(kExceptionObjectReg, bit_cast<int32_t>(raw_exception));
   set_register(kStackTraceObjectReg, bit_cast<int32_t>(raw_stacktrace));
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_MIPS)
 
 #endif  // defined TARGET_ARCH_MIPS