[turbofan] Use CheckMaps in JSGlobalObjectSpecialization.

This is a simple cleanup to use the recently added CheckMaps operator
instead of the hand-crafted map check sequence.

R=epertoso@chromium.org

Review-Url: https://codereview.chromium.org/2199263002
Cr-Commit-Position: refs/heads/master@{#38242}

src/compiler/js-global-object-specialization.cc

@@ -186,17 +186,12 @@ Reduction JSGlobalObjectSpecialization::ReduceJSStoreGlobal(Node* node) {
         value = effect = graph()->NewNode(simplified()->CheckTaggedPointer(),
                                           value, effect, control);
 
-        // Load the {value} map check against the {property_cell} map.
-        Node* value_map = effect =
-            graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()),
-                             value, effect, control);
+        // Check {value} map agains the {property_cell} map.
         Handle<Map> property_cell_value_map(
             Handle<HeapObject>::cast(property_cell_value)->map(), isolate());
-        Node* check = graph()->NewNode(
-            simplified()->ReferenceEqual(Type::Any()), value_map,
-            jsgraph()->HeapConstant(property_cell_value_map));
-        effect =
-            graph()->NewNode(simplified()->CheckIf(), check, effect, control);
+        effect = graph()->NewNode(
+            simplified()->CheckMaps(1), value,
+            jsgraph()->HeapConstant(property_cell_value_map), effect, control);
         property_cell_value_type = Type::TaggedPointer();
       } else {
         // Check that the {value} is a Smi.