Fixes bug where we would occasionally materialize a corrupted object.

runtime/vm/locations.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 "vm/locations.h"
 
 #include "vm/assembler.h"
 #include "vm/il_printer.h"
 #include "vm/intermediate_language.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 198 matching lines @@
   } else if (kind() == kDoubleStackSlot) {
     f->Print("DS%+" Pd "", stack_index());
   } else if (kind() == kQuadStackSlot) {
     f->Print("QS%+" Pd "", stack_index());
   } else {
     f->Print("%s", Name());
   }
 }
 
 
+const char* Location::ToCString() const {
+  char buffer[1024];
+  BufferFormatter bf(buffer, 1024);
+  PrintTo(&bf);
+  return Isolate::Current()->current_zone()->MakeCopyOfString(buffer);
+}
+
+
 void Location::Print() const {
   if (kind() == kStackSlot) {
     OS::Print("S%+" Pd "", stack_index());
   } else {
     OS::Print("%s", Name());
   }
 }
 
 
 void LocationSummary::PrintTo(BufferFormatter* f) const {
@@ skipping 17 matching lines @@
 
   if (!out(0).IsInvalid()) {
     f->Print(" => ");
     out(0).PrintTo(f);
   }
 
   if (always_calls()) f->Print(" C");
 }
 
 }  // namespace dart