Set MethodInvocation.interfaceTarget during type inference.

pkg/front_end/testcases/inference/infer_assign_to_property.dart

Index: pkg/front_end/testcases/inference/infer_assign_to_property.dart
diff --git a/pkg/front_end/testcases/inference/infer_assign_to_property.dart b/pkg/front_end/testcases/inference/infer_assign_to_property.dart
index 0e5c656a077224fea5ba9742eeaa0f3a76a1e1d2..f28a7ae47fdb828b3a71c1f8002b4b90eb6ec6bd 100644
--- a/pkg/front_end/testcases/inference/infer_assign_to_property.dart
+++ b/pkg/front_end/testcases/inference/infer_assign_to_property.dart
@@ -18,9 +18,9 @@ var /*@topType=dynamic*/ v_minus =
 var /*@topType=dynamic*/ v_multiply =
     (/*error:TOP_LEVEL_UNSUPPORTED*/ new A().f *= 1);
 var /*@topType=dynamic*/ v_prefix_pp =
-    (++new A(). /*error:TOP_LEVEL_INSTANCE_GETTER*/ f);
+    (/*@target=num::+*/ ++new A(). /*error:TOP_LEVEL_INSTANCE_GETTER*/ f);
 var /*@topType=dynamic*/ v_prefix_mm =
-    (--new A(). /*error:TOP_LEVEL_INSTANCE_GETTER*/ f);
+    (/*@target=num::-*/ --new A(). /*error:TOP_LEVEL_INSTANCE_GETTER*/ f);
 var /*@topType=dynamic*/ v_postfix_pp =
     (new A(). /*error:TOP_LEVEL_INSTANCE_GETTER*/ f++);
 var /*@topType=dynamic*/ v_postfix_mm =