Remove unnecessary contexts in closure conversion

pkg/kernel/testcases/closures/contexts_in_super_initializers.dart

Index: pkg/kernel/testcases/closures/contexts_in_super_initializers.dart
diff --git a/pkg/kernel/testcases/closures/contexts_in_super_initializers.dart b/pkg/kernel/testcases/closures/contexts_in_super_initializers.dart
new file mode 100644
index 0000000000000000000000000000000000000000..528b76b4c0470e4d3f0a49b29096c4abeac5dafe
--- /dev/null
+++ b/pkg/kernel/testcases/closures/contexts_in_super_initializers.dart
@@ -0,0 +1,26 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// The purpose of this test is to detect that no unnecessary contexts are
+// created when a constructor parameter is used in its super initializer.  No
+// contexts should be created either in the initializer list or in the
+// constructor body.
+
+class X {}
+
+class Y {}
+
+class A {
+  X x;
+  Y y;
+  A(this.x, this.y);
+}
+
+class B extends A {
+  B(X x, Y y) : super(x, y) {}
+}
+
+main() {
+  B b = new B(new X(), new Y());
+}