allow await to be any value, fixes part of #264

test/checker/checker_test.dart

Index: test/checker/checker_test.dart
diff --git a/test/checker/checker_test.dart b/test/checker/checker_test.dart
index 77ec7202cdd854411db0788020dbb1f77b8afd8f..1eee30980d8a1d454c193e1a35ab7bd38ccff6f9 100644
--- a/test/checker/checker_test.dart
+++ b/test/checker/checker_test.dart
@@ -2692,11 +2692,16 @@ void main() {
         Future<int> z;
 
         void baz() async {
-          int a = /*info:DynamicCast*/await /*info:DynamicCast*/x;
-          int b = await /*severe:StaticTypeError*/y;
+          int a = /*info:DynamicCast*/await x;
+          int b = await y;
           int c = await z;
           String d = /*severe:StaticTypeError*/await z;
         }
+
+        Future<bool> get issue_264 async {
+          await 42;
+          return false;
+        }
     '''
     }));