Debug garbage collector does not correctly remove cross-gen garbage

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 3346 matching lines @@
     String& key = String::Handle();
     key ^= OneByteString::New("key", Heap::kOld);
     String& value = String::Handle();
     value ^= OneByteString::New("value", Heap::kNew);
     weak ^= WeakProperty::New(Heap::kNew);
     weak.set_key(key);
     weak.set_value(value);
     key ^= OneByteString::null();
     value ^= OneByteString::null();
   }
-  isolate->heap()->CollectAllGarbage();
+  isolate->heap()->CollectGarbage(Heap::kNew);

[rmacnak, 2017/06/19 19:29:00]

These shouldn't need to change.

+  isolate->heap()->CollectGarbage(Heap::kOld);
   // Weak property key and value should survive due to cross-generation
   // pointers.
   EXPECT(weak.key() != Object::null());
   EXPECT(weak.value() != Object::null());
   {
     // Weak property and value in old. Key in new.
     HANDLESCOPE(thread);
     String& key = String::Handle();
     key ^= OneByteString::New("key", Heap::kNew);
     String& value = String::Handle();
     value ^= OneByteString::New("value", Heap::kOld);
     weak ^= WeakProperty::New(Heap::kOld);
     weak.set_key(key);
     weak.set_value(value);
     key ^= OneByteString::null();
     value ^= OneByteString::null();
   }
-  isolate->heap()->CollectAllGarbage();
+  isolate->heap()->CollectGarbage(Heap::kNew);
+  isolate->heap()->CollectGarbage(Heap::kOld);
   // Weak property key and value should survive due to cross-generation
   // pointers.
   EXPECT(weak.key() != Object::null());
   EXPECT(weak.value() != Object::null());
   {
     // Weak property and value in new. Key is a Smi.
     HANDLESCOPE(thread);
     Integer& key = Integer::Handle();
     key ^= Integer::New(31);
     String& value = String::Handle();
@@ skipping 1326 matching lines @@
   // utf32->utf16 conversion.
   int32_t char_codes[] = {0,      0x0a,   0x0d,   0x7f,   0xff,
                           0xffff, 0xd800, 0xdc00, 0xdbff, 0xdfff};
 
   const String& str =
       String::Handle(String::FromUTF32(char_codes, ARRAY_SIZE(char_codes)));
   EXPECT(str.Equals(char_codes, ARRAY_SIZE(char_codes)));
 }
 
 }  // namespace dart