Debug garbage collector does not correctly remove cross-gen garbage

runtime/vm/heap.h

 // 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.
 
 #ifndef RUNTIME_VM_HEAP_H_
 #define RUNTIME_VM_HEAP_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/flags.h"
@@ skipping 288 matching lines @@
   // Visit all objects, including FreeListElement "objects". Caller must ensure
   // concurrent sweeper is not running, and the visitor must not allocate.
   void VisitObjects(ObjectVisitor* visitor) const;
   void VisitObjectsNoImagePages(ObjectVisitor* visitor) const;
   void VisitObjectsImagePages(ObjectVisitor* visitor) const;
 
   // Like Verify, but does not wait for concurrent sweeper, so caller must
   // ensure thread-safety.
   bool VerifyGC(MarkExpectation mark_expectation = kForbidMarked) const;
 
+  void EvacuateNewSpaceGarbage(Thread* thread, GCReason reason);

[rmacnak, 2017/06/30 22:24:56]

Consider just "EvacuateNewSpace", since the garbage isn't being evacuated.

Place below the "helper functions" comment

[danunez, 2017/06/30 22:33:58]

Done.

   // Helper functions for garbage collection.
   void CollectNewSpaceGarbage(Thread* thread,
                               ApiCallbacks api_callbacks,
                               GCReason reason);
   void CollectOldSpaceGarbage(Thread* thread,
                               ApiCallbacks api_callbacks,
                               GCReason reason);
 
   // GC stats collection.
   void RecordBeforeGC(Space space, GCReason reason);
@@ skipping 74 matching lines @@
 // Note: During this scope, the code pages are non-executable.
 class WritableVMIsolateScope : StackResource {
  public:
   explicit WritableVMIsolateScope(Thread* thread);
   ~WritableVMIsolateScope();
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_HEAP_H_