ignore `@proxy` in strong mode

pkg/analyzer/test/src/task/strong/inferred_type_test.dart

Index: pkg/analyzer/test/src/task/strong/inferred_type_test.dart
diff --git a/pkg/analyzer/test/src/task/strong/inferred_type_test.dart b/pkg/analyzer/test/src/task/strong/inferred_type_test.dart
index 802292b71f08bee21f24b2064e9db54807b462e9..efc0677583d2f22aaf9e2f0be577abc459b60890 100644
--- a/pkg/analyzer/test/src/task/strong/inferred_type_test.dart
+++ b/pkg/analyzer/test/src/task/strong/inferred_type_test.dart
@@ -1031,7 +1031,7 @@ void main () {
     Function2<int, int> l0 = /*info:INFERRED_TYPE_CLOSURE*/(x) => x;
     Function2<int, int> l1 = /*info:INFERRED_TYPE_CLOSURE*/(x) => x+1;
     Function2<int, String> l2 = /*info:INFERRED_TYPE_CLOSURE, error:INVALID_ASSIGNMENT*/(x) => x;
-    Function2<int, String> l3 = /*info:INFERRED_TYPE_CLOSURE*/(x) => /*info:DYNAMIC_CAST, info:DYNAMIC_INVOKE*/x.substring(3);
+    Function2<int, String> l3 = /*info:INFERRED_TYPE_CLOSURE*/(x) => /*info:DYNAMIC_CAST, info:DYNAMIC_INVOKE*/x./*error:UNDEFINED_METHOD*/substring(3);
     Function2<String, String> l4 = /*info:INFERRED_TYPE_CLOSURE*/(x) => x.substring(3);
   }
 }
@@ -1197,7 +1197,7 @@ void main () {
     x = /*info:INFERRED_TYPE_CLOSURE*/<T>(x) => x+1;
     var y = int2String;
     y = /*info:INFERRED_TYPE_CLOSURE, error:INVALID_ASSIGNMENT*/<T>(x) => x;
-    y = /*info:INFERRED_TYPE_CLOSURE, info:INFERRED_TYPE_CLOSURE*/<T>(x) => /*info:DYNAMIC_INVOKE, info:DYNAMIC_CAST*/x.substring(3);
+    y = /*info:INFERRED_TYPE_CLOSURE, info:INFERRED_TYPE_CLOSURE*/<T>(x) => /*info:DYNAMIC_INVOKE, info:DYNAMIC_CAST*/x./*error:UNDEFINED_METHOD*/substring(3);
     var z = string2String;
     z = /*info:INFERRED_TYPE_CLOSURE*/<T>(x) => x.substring(3);
   }
@@ -1244,7 +1244,7 @@ void main () {
     x = /*info:INFERRED_TYPE_CLOSURE*//*<T>*/(x) => x+1;
     var y = int2String;
     y = /*info:INFERRED_TYPE_CLOSURE, error:INVALID_ASSIGNMENT*//*<T>*/(x) => x;
-    y = /*info:INFERRED_TYPE_CLOSURE, info:INFERRED_TYPE_CLOSURE*//*<T>*/(x) => /*info:DYNAMIC_INVOKE, info:DYNAMIC_CAST*/x.substring(3);
+    y = /*info:INFERRED_TYPE_CLOSURE, info:INFERRED_TYPE_CLOSURE*//*<T>*/(x) => /*info:DYNAMIC_INVOKE, info:DYNAMIC_CAST*/x./*error:UNDEFINED_METHOD*/substring(3);
     var z = string2String;
     z = /*info:INFERRED_TYPE_CLOSURE*//*<T>*/(x) => x.substring(3);
   }