Fix invalid cast of heap constant object.

src/compiler/representation-change.h

Index: src/compiler/representation-change.h
diff --git a/src/compiler/representation-change.h b/src/compiler/representation-change.h
index ffb86d16a26709d657296ab749f9ee50716566e0..34dadf1317efbf475d124b010ef176bb4f9bb4b6 100644
--- a/src/compiler/representation-change.h
+++ b/src/compiler/representation-change.h
@@ -292,7 +292,8 @@ class RepresentationChanger {
     // Eagerly fold representation changes for constants.
     switch (node->opcode()) {
       case IrOpcode::kHeapConstant: {
-        Handle<Object> value = OpParameter<Unique<Object> >(node).handle();
+        Handle<HeapObject> value =
+            OpParameter<Unique<HeapObject>>(node).handle();
         DCHECK(value.is_identical_to(factory()->true_value()) ||
                value.is_identical_to(factory()->false_value()));
         return jsgraph()->Int32Constant(