Debug garbage collector does not correctly remove cross-gen garbage

runtime/vm/object_test.cc

Index: runtime/vm/object_test.cc
diff --git a/runtime/vm/object_test.cc b/runtime/vm/object_test.cc
index 0e04a7e3151de69a296c6ea21a609ee920bb1b8e..3a78c140ee201a9fb247c66b43b3070f6da08453 100644
--- a/runtime/vm/object_test.cc
+++ b/runtime/vm/object_test.cc
@@ -3382,7 +3382,8 @@ ISOLATE_UNIT_TEST_CASE(WeakProperty_PreserveCrossGen) {
     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());
@@ -3400,7 +3401,8 @@ ISOLATE_UNIT_TEST_CASE(WeakProperty_PreserveCrossGen) {
     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());
@@ -3453,7 +3455,8 @@ ISOLATE_UNIT_TEST_CASE(WeakProperty_PreserveCrossGen) {
     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());
@@ -3470,7 +3473,8 @@ ISOLATE_UNIT_TEST_CASE(WeakProperty_PreserveCrossGen) {
     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());