Fix async/await type checking in analyzer.

pkg/analyzer/lib/src/generated/testing/test_type_provider.dart

Index: pkg/analyzer/lib/src/generated/testing/test_type_provider.dart
diff --git a/pkg/analyzer/lib/src/generated/testing/test_type_provider.dart b/pkg/analyzer/lib/src/generated/testing/test_type_provider.dart
index 8cd47724eabc95728e51f4d0fca0cfd6d9bc4e20..9a719d4acb92ff7b60d8fa3da9376fc47f2ae17d 100644
--- a/pkg/analyzer/lib/src/generated/testing/test_type_provider.dart
+++ b/pkg/analyzer/lib/src/generated/testing/test_type_provider.dart
@@ -47,6 +47,11 @@ class TestTypeProvider implements TypeProvider {
   InterfaceType _functionType;
 
   /**
+   * THe type representing the built-in type 'Future'
+   */
+  InterfaceType _futureType;
+
+  /**
    * The type representing the built-in type 'int'.
    */
   InterfaceType _intType;
@@ -172,6 +177,14 @@ class TestTypeProvider implements TypeProvider {
   }
 
   @override
+  InterfaceType get futureType {
+    if (_futureType == null) {
+      _futureType = ElementFactory.classElement2("Future", ["T"]).type;
+    }
+    return _futureType;
+  }
+
+  @override
   InterfaceType get intType {
     if (_intType == null) {
       _initializeNumericTypes();