Fix also type inference for enum method invocation.

pkg/analyzer/test/src/summary/resynthesize_common.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.src.serialization.elements_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 5465 matching lines @@
   static const E b;
   static const E c;
 }
 final dynamic vValue;
 final dynamic vValues;
 final dynamic vIndex;
 ''');
     }
   }
 
+  test_constExpr_pushReference_enum_method() {
+    var library = checkLibrary('''
+enum E {a}
+final vToString = E.a.toString();
+''');
+    if (isStrongMode) {
+      checkElementText(
+          library,
+          r'''
+enum E {
+  final int index;
+  static const List<E> values;
+  static const E a;
+}
+final String vToString;
+''');
+    } else {
+      checkElementText(
+          library,
+          r'''
+enum E {
+  final int index;
+  static const List<E> values;
+  static const E a;
+}
+final dynamic vToString;
+''');
+    }
+  }
+
   test_constExpr_pushReference_field_simpleIdentifier() {
     var library = checkLibrary('''
 class C {
   static const a = b;
   static const b = null;
 }
 ''');
     if (isStrongMode) {
       checkElementText(
           library,
@@ skipping 9455 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }