Migrate tests for initializing formals

pkg/dev_compiler/test/codegen/language/initializing_formal_type_test.dart

Index: pkg/dev_compiler/test/codegen/language/initializing_formal_type_test.dart
diff --git a/pkg/dev_compiler/test/codegen/language/initializing_formal_type_test.dart b/pkg/dev_compiler/test/codegen/language/initializing_formal_type_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..af4444481f44c8070642c7f1356d29ae3bcb7b3e
--- /dev/null
+++ b/pkg/dev_compiler/test/codegen/language/initializing_formal_type_test.dart
@@ -0,0 +1,25 @@
+// Copyright (c) 2016, 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.
+//
+// DartOptions=--initializing-formal-access
+// VMOptions=--initializing-formal-access
+
+import "package:expect/expect.dart";
+
+class A {
+  num x;
+  double y;
+  // Finding the type of an initializing formal: should cause a warning
+  // in the initializer but not the body, because the former has type
+  // `int` and the latter has type `num`.
+  A(int this.x) : y = x {

[eernst, 2016/11/30 10:22:46]

I would expect the above initialization to be an error in strong mode as well:
It is an `int` value being stored in a `double` variable.

So it should get the same treatment as initializing_formal_final_test.dart (and
I created a similar issue https://github.com/dart-lang/sdk/issues/27936, to
check that we get the correct warning from dart2js).

I can see that there is an entry in 'not_yet_strong_tests.dart' below for this
test, but it is actually not a test which is intended to be updated such that it
has no type violations, it is a test that creates a typing situation which must
be detected and rejected (in strong mode, or warned about in standard mode). So
how do you usually handle that?

+    y = x;
+  }
+}
+
+main() {
+  A a = new A(null);
+  Expect.equals(a.x, null);
+  Expect.equals(a.y, null);
+}