Fix type check to perform a subtype test at top level instead of an

runtime/vm/exceptions.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/exceptions.h"
 
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
 #include "vm/flags.h"
 #include "vm/object.h"
@@ skipping 205 matching lines @@
   // Print type error information before throwing the error when debugging.
   if (FLAG_print_stack_trace_at_throw) {
     if (!malformed_error.IsNull()) {
       OS::Print("%s\n", malformed_error.ToCString());
     }
     intptr_t line, column;
     script.GetTokenLocation(location, &line, &column);
     OS::Print("'%s': Failed type check: line %d pos %d: ",
               String::Handle(script.url()).ToCString(), line, column);
     if (!dst_name.IsNull() && (dst_name.Length() > 0)) {
-      OS::Print("type '%s' is not assignable to type '%s' of '%s'.\n",
+      OS::Print("type '%s' is not a subtype of type '%s' of '%s'.\n",
                 src_type_name.ToCString(),
                 dst_type_name.ToCString(),
                 dst_name.ToCString());
     } else {
-      OS::Print("malformed type used in type test.\n",
+      OS::Print("malformed type used.\n",
                 String::Handle(script.url()).ToCString(),
                 line, column);
     }
   }
   // Throw TypeError instance.
   Exceptions::Throw(type_error);
   UNREACHABLE();
 }
 
 
@@ skipping 93 matching lines @@
       break;
     case kIllegalJSRegExp:
       class_name = String::NewSymbol("IllegalJSRegExpException");
       break;
   }
 
   return DartLibraryCalls::ExceptionCreate(class_name, arguments);
 }
 
 }  // namespace dart