Another Babel reexport check form

[guybedford]

Posted #42 with a failing test for the following reexport form in Babel:

        var _p = require("p");
        Object.keys(_p).forEach(function (key) {
          if (key === "default" || key === "__esModule") return;
          if (key in exports && exports[key] === _p[key]) return;
          Object.defineProperty(exports, key, {
            enumerable: true,
            get: function () {
              return _p[key];
            }
          });
        });

We should probably add support for the if (key in exports && exports[key] === _p[key]) return; line here I think.

[guybedford]

Turns out the test was incorrectly constructed here.