Fix AST summarization of synthetic function types and method tear-offs.

pkg/analyzer/test/src/summary/resynthesize_test.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 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
@@ skipping 640 matching lines @@
     ElementImpl oImpl = getActualElement(original, desc);
     if (oImpl == null && rImpl == null) {
       return;
     }
     if (oImpl is PrefixElement) {
       // TODO(scheglov) prefixes cannot be resynthesized
       return;
     }
     expect(original, isNotNull);
     expect(resynthesized, isNotNull, reason: desc);
-    expect(rImpl.runtimeType, oImpl.runtimeType);
+    if (rImpl is DefaultParameterElementImpl && oImpl is ParameterElementImpl) {
+      // This is ok provided the resynthesized parameter element doesn't have
+      // any evaluation result.
+      expect(rImpl.evaluationResult, isNull);
+    } else {
+      expect(rImpl.runtimeType, oImpl.runtimeType);
+    }
     expect(resynthesized.kind, original.kind);
     expect(resynthesized.location, original.location, reason: desc);
     expect(resynthesized.name, original.name);
     expect(resynthesized.nameOffset, original.nameOffset, reason: desc);
     expect(rImpl.codeOffset, oImpl.codeOffset, reason: desc);
     expect(rImpl.codeLength, oImpl.codeLength, reason: desc);
     expect(resynthesized.documentationComment, original.documentationComment,
         reason: desc);
     expect(resynthesized.docRange, original.docRange, reason: desc);
     compareMetadata(resynthesized.metadata, original.metadata, desc);
@@ skipping 2547 matching lines @@
 Stream s;
 ''');
   }
 
   test_imports() {
     addLibrarySource('/a.dart', 'library a; class C {}');
     addLibrarySource('/b.dart', 'library b; class D {}');
     checkLibrary('import "a.dart"; import "b.dart"; C c; D d;');
   }
 
+  void test_inferedType_usesSyntheticFunctionType_functionTypedParam() {
+    checkLibrary('''
+int f(int x(String y)) => null;
+String g(int x(String y)) => null;
+var v = [f, g];
+''');
+  }
+
   test_inferred_function_type_for_variable_in_generic_function() {
     // In the code below, `x` has an inferred type of `() => int`, with 2
     // (unused) type parameters from the enclosing top level function.
     checkLibrary('''
 f<U, V>() {
   var x = () => 0;
 }
 ''');
   }
 
@@ skipping 1169 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }