Add 64-bit stubs to call into the runtime and to call native functions.

runtime/vm/assembler.cc

 // Copyright (c) 2011, 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/assembler.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
 #include "vm/memory_region.h"
 #include "vm/utils.h"
 #include "vm/zone.h"
@@ skipping 135 matching lines @@
   // Since we are going to store the handle as part of the fixup information
   // the handle needs to be a zone handle.
   ASSERT(object.IsZoneHandle());
   EmitFixup(new PatchCodeWithHandle(pointer_offsets_, object));
   cursor_ += kWordSize;  // Reserve space for pointer.
 }
 
 
 // Shared macros are implemented here.
 void Assembler::Unimplemented(const char* message) {
-  Stop("unimplemented");
+  const char* format = "Unimplemented: %s";
+  const intptr_t len = snprintf(NULL, 0, format, message);
+  char* buffer = reinterpret_cast<char*>(malloc(len + 1));
+  snprintf(buffer, len + 1, format, message);
+  Stop(buffer);
 }
 
 
 void Assembler::Untested(const char* message) {
-  Stop("untested");
+  const char* format = "Untested: %s";
+  const intptr_t len = snprintf(NULL, 0, format, message);
+  char* buffer = reinterpret_cast<char*>(malloc(len + 1));
+  snprintf(buffer, len + 1, format, message);
+  Stop(buffer);
 }
 
 
 void Assembler::Unreachable(const char* message) {
-  Stop("unreachable");
+  const char* format = "Unreachable: %s";
+  const intptr_t len = snprintf(NULL, 0, format, message);
+  char* buffer = reinterpret_cast<char*>(malloc(len + 1));
+  snprintf(buffer, len + 1, format, message);
+  Stop(buffer);
 }
 
 }  // namespace dart