Use stability to only conditionally flush information from the map check table.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index f5c5c32f406044898596a28102d61b0a61749f0e..224457ab4bd1d64f8d0df696f55f54e178cf8aa2 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -3949,7 +3949,7 @@ void HAllocate::CreateFreeSpaceFiller(int32_t free_space_size) {
   free_space_instr->InsertBefore(this);
   HConstant* filler_map = HConstant::CreateAndInsertAfter(
       zone, Unique<Map>::CreateImmovable(
-          isolate()->factory()->free_space_map()), free_space_instr);
+          isolate()->factory()->free_space_map()), true, free_space_instr);
   HInstruction* store_map = HStoreNamedField::New(zone, context(),
       free_space_instr, HObjectAccess::ForMap(), filler_map);
   store_map->SetFlag(HValue::kHasNoObservableSideEffects);