Do not eagerly finalize when optimizing. Remove allocation of temporary strings in new space.

runtime/vm/class_finalizer.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/class_finalizer.h"
 
 #include "vm/code_generator.h"
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
@@ skipping 827 matching lines @@
             instantiated_bound.Equals(declared_bound))) {
         // If type_arg is a type parameter, its declared bound may not be
         // resolved yet.
         if (type_arg.IsTypeParameter()) {
           const Class& type_arg_cls = Class::Handle(
               TypeParameter::Cast(type_arg).parameterized_class());
           const AbstractType& bound = AbstractType::Handle(
               TypeParameter::Cast(type_arg).bound());
           ResolveType(type_arg_cls, bound);
         }
-        if (!type_param.CheckBound(type_arg, instantiated_bound, &error) &&
-            error.IsNull()) {
+        // This may be called only if type needs to be finalized, therefore
+        // seems OK to allocate temporary type in old space.

[regis, 2015/09/25 20:55:23]

The comment is hard to read. I am not sure what is the "temporary type".
How about simply: Allocate finalized types in old space.

[srdjan, 2015/09/25 21:15:59]

Done.

+        if (!type_param.CheckBound(type_arg, instantiated_bound,
+                &error, Heap::kOld) && error.IsNull()) {
           // The bound cannot be checked at compile time; postpone to run time.
           type_arg = BoundedType::New(type_arg, instantiated_bound, type_param);
           arguments.SetTypeAt(offset + i, type_arg);
         }
       }
       if (!error.IsNull() && bound_error->IsNull()) {
         *bound_error = error.raw();
       }
     }
   }
@@ skipping 2358 matching lines @@
   ASSERT(fields_array.Length() == ByteBuffer::NumberOfFields());
   field ^= fields_array.At(0);
   ASSERT(field.Offset() == ByteBuffer::data_offset());
   name ^= field.name();
   expected_name ^= String::New("_data");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
 #endif
 }
 
 }  // namespace dart