Try catch do not introduce block scope for new declarations

try-catch-block-scope.js

(function () {
  'use strict';

  try {
    undefined();
  } catch (err) {
    var a = 5;
    console.log(a);     // 5
    console.log(err);   // TypeError: undefined is not a function(…)
  }    
  console.log(a);  // 5   This should be undefined if a was scoped only to catch block. But it isn't.
})();