Lookup getter/setter symbols before alllocating them, thus eliminating extra String allocations in …

runtime/vm/object_test.cc

 // Copyright (c) 2012, 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 "platform/globals.h"
 
 #include "vm/assembler.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 4761 matching lines @@
 
     uint16_t characters2[] =
         { 'a', '\n', '\f', '\b', '\t', '\v', '\r', '\\', '$', 'z' };
     intptr_t len2 = ARRAY_SIZE(characters2);
 
     const String& str2 = String::Handle(
         ExternalTwoByteString::New(characters2, len2, NULL, NULL, Heap::kNew));
     const String* data[3] = { &str1, &Symbols::Dot(), &str2 };
     CheckConcatAll(data, 3);
   }
+
+  {
+    const String& empty = String::Handle(String::New(""));
+    const String* data[3] = { &Symbols::FallThroughError(),
+                              &empty,
+                              &Symbols::isPaused() };
+    CheckConcatAll(data, 3);
+  }
 }
 
 }  // namespace dart