add object getter memoization and this shorthand to playground

test/fixtures/transformation/playground/object-getter-memoization/actual.js

@@ -0,0 +1,19 @@
+class Foo {
+  memo bar() {
+    return complex();
+  }
+
+  memo [bar]() {
+    return complex();
+  }
+}
+
+var foo = {
+  memo bar() {
+    return complex();
+  },
+
+  memo [bar]() {
+    return complex();
+  }
+};

test/fixtures/transformation/playground/object-getter-memoization/expected.js

@@ -0,0 +1,53 @@
+"use strict";
+
+var _classProps = function (child, staticProps, instanceProps) {
+  if (staticProps) Object.defineProperties(child, staticProps);
+  if (instanceProps) Object.defineProperties(child.prototype, instanceProps);
+};
+
+var Foo = (function () {
+  var Foo = function Foo() {};
+
+  _classProps(Foo, null, (function (_ref) {
+    _ref[bar] = {
+      get: function () {
+        if (this._memoDone) return this._memo;
+        this._memoDone = true;
+        return this._memo = complex();
+      }
+    };
+    return _ref;
+  })({
+    bar: {
+      get: function () {
+        if (this._barDone) return this._bar;
+        this._barDone = true;
+        return this._bar = complex();
+      }
+    }
+  }));
+
+  return Foo;
+})();
+
+var foo = (function (_foo) {
+  _foo[bar] = function () {
+    if (this._memo2Done) return this._memo2;
+    this._memo2Done = true;
+    return this._memo2 = complex();
+  };
+
+  return _foo;
+})((function (_ref2) {
+  Object.defineProperties(_ref2, {
+    bar: {
+      get: function () {
+        if (this._barDone) return this._bar;
+        this._barDone = true;
+        return this._bar = complex();
+      }
+    }
+  });
+
+  return _ref2;
+})({}));