Function setToStringTag

lib/web/polyfill.js:88–90

(it, tag, stat)

// http://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring
var toString = ObjectProto[TO_STRING];
function setToStringTag(it, tag, stat){
  if(it && !has(it = stat ? it : it[PROTOTYPE], SYMBOL_TAG))hidden(it, SYMBOL_TAG, tag);
}
function cof(it){
  return toString.call(it).slice(8, -1);
}