[heap] Set progress bar flag for FixedArray upon allocation

test/cctest/heap/test-lab.cc

Index: test/cctest/heap/test-lab.cc
diff --git a/test/cctest/heap/test-lab.cc b/test/cctest/heap/test-lab.cc
index 3730e4a58975db458049d6674fdad3470d9a697d..b625206f48fb8ca1331e2e11a0188efd4eed61dd 100644
--- a/test/cctest/heap/test-lab.cc
+++ b/test/cctest/heap/test-lab.cc
@@ -19,8 +19,7 @@ namespace internal {
 static Address AllocateLabBackingStore(Heap* heap, intptr_t size_in_bytes) {
   AllocationResult result = heap->old_space()->AllocateRaw(
       static_cast<int>(size_in_bytes), kDoubleAligned);
-  Object* obj = result.ToObjectChecked();
-  Address adr = HeapObject::cast(obj)->address();
+  Address adr = result.ToObjectChecked()->address();
   return adr;
 }