always emit lazy field if overriding static

lib/src/compiler/js_field_storage.dart

Index: lib/src/compiler/js_field_storage.dart
diff --git a/lib/src/compiler/js_field_storage.dart b/lib/src/compiler/js_field_storage.dart
index b66d41c6cc214c9c6474caa038ba93acf75c5d35..8c29ac4cb725beb38309970927721e731588a398 100644
--- a/lib/src/compiler/js_field_storage.dart
+++ b/lib/src/compiler/js_field_storage.dart
@@ -16,22 +16,15 @@ class PropertyOverrideResult {
   PropertyOverrideResult(this.foundGetter, this.foundSetter);
 }
 
-PropertyOverrideResult checkForPropertyOverride(FieldElement field,
-    List<ClassElement> superclasses, ExtensionTypeSet extensionTypes) {
+PropertyOverrideResult checkForPropertyOverride(
+    FieldElement field, List<ClassElement> superclasses) {
   bool foundGetter = false;
   bool foundSetter = false;
 
   for (var superclass in superclasses) {
-    // Stop if we reach a native type.
-    if (extensionTypes.isNativeClass(superclass)) break;
-
     var superprop = getProperty(superclass, field.library, field.name);
     if (superprop == null) continue;
 
-    // Static fields can override superclass static fields. However, we need to
-    // handle the case where they override a getter or setter.
-    if (field.isStatic && !superprop.isSynthetic) continue;
-
     var getter = superprop.getter;
     bool hasGetter = getter != null && !getter.isAbstract;
     if (hasGetter) foundGetter = true;