Enable top level inference of instance property gets/sets.

pkg/front_end/testcases/inference_new/infer_assign_to_property.dart.direct.expect

Index: pkg/front_end/testcases/inference_new/infer_assign_to_property.dart.direct.expect
diff --git a/pkg/front_end/testcases/inference_new/infer_assign_to_property.dart.direct.expect b/pkg/front_end/testcases/inference_new/infer_assign_to_property.dart.direct.expect
new file mode 100644
index 0000000000000000000000000000000000000000..49cb344f44ee843a76773a139a896f9619564683
--- /dev/null
+++ b/pkg/front_end/testcases/inference_new/infer_assign_to_property.dart.direct.expect
@@ -0,0 +1,19 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  field core::int f = null;
+  constructor •() → void
+    : super core::Object::•()
+    ;
+}
+static field dynamic v_assign = new self::A::•().f = 1;
+static field dynamic v_plus = let final dynamic #t1 = new self::A::•() in #t1.f = #t1.f.+(1);
+static field dynamic v_minus = let final dynamic #t2 = new self::A::•() in #t2.f = #t2.f.-(1);
+static field dynamic v_multiply = let final dynamic #t3 = new self::A::•() in #t3.f = #t3.f.*(1);
+static field dynamic v_prefix_pp = let final dynamic #t4 = new self::A::•() in #t4.f = #t4.f.+(1);
+static field dynamic v_prefix_mm = let final dynamic #t5 = new self::A::•() in #t5.f = #t5.f.-(1);
+static field dynamic v_postfix_pp = let final dynamic #t6 = new self::A::•() in let final dynamic #t7 = #t6.f in let final dynamic #t8 = #t6.f = #t7.+(1) in #t7;
+static field dynamic v_postfix_mm = let final dynamic #t9 = new self::A::•() in let final dynamic #t10 = #t9.f in let final dynamic #t11 = #t9.f = #t10.-(1) in #t10;
+static method main() → dynamic {}