fix #25794, infer parameter type from default value

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 4089 matching lines @@
   }
 
   test_operator_index_set() {
     checkLibrary('class C { void operator[]=(int i, bool v) {} }');
   }
 
   test_operator_less_equal() {
     checkLibrary('class C { bool operator<=(C other) => false; }');
   }
 
-  test_parameterTypeNotInferred_constructor() {
-    // Strong mode doesn't do type inference on constructor parameters, so it's
-    // ok that we don't store inferred type info for them in summaries.
+  test_parameterType_inferred_constructor() {
     checkLibrary('''
 class C {
   C.positional([x = 1]);
   C.named({x: 1});
 }
 ''');
   }
 
-  test_parameterTypeNotInferred_initializingFormal() {
-    // Strong mode doesn't do type inference on initializing formals, so it's
-    // ok that we don't store inferred type info for them in summaries.
-    checkLibrary('''
-class C {
-  var x;
-  C.positional([this.x = 1]);
-  C.named({this.x: 1});
-}
-''');
-  }
-
-  test_parameterTypeNotInferred_staticMethod() {
-    // Strong mode doesn't do type inference on parameters of static methods,
-    // so it's ok that we don't store inferred type info for them in summaries.
+  test_parameterType_inferred_staticMethod() {
     checkLibrary('''
 class C {
   static void positional([x = 1]) {}
   static void named({x: 1}) {}
 }
 ''');
   }
 
-  test_parameterTypeNotInferred_topLevelFunction() {
-    // Strong mode doesn't do type inference on parameters of top level
-    // functions, so it's ok that we don't store inferred type info for them in
-    // summaries.
+  test_parameterType_inferred_topLevelFunction() {
     checkLibrary('''
 void positional([x = 1]) {}
 void named({x: 1}) {}
 ''');
   }
 
+  test_parameterTypeNotInferred_initializingFormal() {
+    // Strong mode doesn't do type inference on initializing formals, so it's
+    // ok that we don't store inferred type info for them in summaries.
+    checkLibrary('''
+class C {
+  var x;
+  C.positional([this.x = 1]);
+  C.named({this.x: 1});
+}
+''');
+  }
+
   test_parts() {
     addSource('/a.dart', 'part of my.lib;');
     addSource('/b.dart', 'part of my.lib;');
     checkLibrary('library my.lib; part "a.dart"; part "b.dart";');
   }
 
   test_propagated_type_refers_to_closure() {
     checkLibrary('''
 void f() {
   var x = () => 0;
@@ skipping 455 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }