Revert "Modifies the debug garbage collector (CollectAllGarbage()) to correctly remove inter-genera…

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 2a6d787dde10a2a504f68e54caa6ddfcd6f90140..0e04a7e3151de69a296c6ea21a609ee920bb1b8e 100644
--- a/runtime/vm/object_test.cc
+++ b/runtime/vm/object_test.cc
@@ -3382,8 +3382,7 @@ ISOLATE_UNIT_TEST_CASE(WeakProperty_PreserveCrossGen) {
     key ^= OneByteString::null();
     value ^= OneByteString::null();
   }
-  isolate->heap()->CollectGarbage(Heap::kNew);
-  isolate->heap()->CollectGarbage(Heap::kOld);
+  isolate->heap()->CollectAllGarbage();
   // Weak property key and value should survive due to cross-generation
   // pointers.
   EXPECT(weak.key() != Object::null());
@@ -3401,8 +3400,7 @@ ISOLATE_UNIT_TEST_CASE(WeakProperty_PreserveCrossGen) {
     key ^= OneByteString::null();
     value ^= OneByteString::null();
   }
-  isolate->heap()->CollectGarbage(Heap::kNew);
-  isolate->heap()->CollectGarbage(Heap::kOld);
+  isolate->heap()->CollectAllGarbage();
   // Weak property key and value should survive due to cross-generation
   // pointers.
   EXPECT(weak.key() != Object::null());