Implementation of modified scoping for initializing formals.

tests/language/initializing_formal_scope_test.dart

Index: tests/language/initializing_formal_scope_test.dart
diff --git a/tests/language/initializing_formal_capture_test.dart b/tests/language/initializing_formal_scope_test.dart
similarity index 54%
copy from tests/language/initializing_formal_capture_test.dart
copy to tests/language/initializing_formal_scope_test.dart
index 7ad3f083cc185754bd31b937bbfba57421445846..dd85fada3582b3f8f946eb73ee5084768871d976 100644
--- a/tests/language/initializing_formal_capture_test.dart
+++ b/tests/language/initializing_formal_scope_test.dart
@@ -6,14 +6,20 @@
 
 import "package:expect/expect.dart";
 
+// Duplicate definition checks for `this.x` will check the scopes associated
+// with the constructor, not all enclosing scopes; so this is not a conflict.
+var x;
+
 class A {
-  var x, y;
-  A(this.x) : y = (() => x);
+  var x;
+  A(this.x) {
+    // In the body the field is in scope, not the initializing formal;
+    // so we can use the setter.
+    x += 1;
+  }
 }
 
 main() {
   A a = new A(2);
-  a.x = 3;
   Expect.equals(a.x, 3);
-  Expect.equals(a.y(), 2);
 }