dart2js curiosities

c1.dart.js

// Curiosity #1
// ------------

function dart() {
  this.x = 0;
  delete this.x;
}
var A = new dart;

c2.dart.js

// Curiosity #2
// ------------

function convertToFastObject(properties) {
  function MyClass() {}
  MyClass.prototype = properties;
  new MyClass();
  return properties;
}
A = convertToFastObject(A);