fixes #52, fields shadowing getters/setters or other fields

test/codegen/expect/methods.js

Index: test/codegen/expect/methods.js
diff --git a/test/codegen/expect/methods.js b/test/codegen/expect/methods.js
index 708b0ce457c45f68eb0864161f508121862d41f6..d8d381a37b2c6a57208f2cd0fa79cff77a081897 100644
--- a/test/codegen/expect/methods.js
+++ b/test/codegen/expect/methods.js
@@ -46,9 +46,13 @@ var methods;
       return core.print(`hello from ${x}`);
     }
   }
+  let bar = Symbol('bar');
   class Foo extends core.Object {
     Foo() {
-      this.bar = new Bar();
+      this[bar] = new Bar();
+    }
+    get bar() {
+      return this[bar];
     }
   }
   // Function test: () → dynamic