Simplifying _.bind to remove ES5 edge cases

test/functions.js

@@ -34,10 +34,7 @@ $(document).ready(function() {
     // To test this with a modern browser, set underscore's nativeBind to undefined
     var F = function () { return this; };
     var Boundf = _.bind(F, {hello: "moe curly"});
-    var newBoundf = new Boundf();
-    equal(newBoundf.hello, undefined, "function should not be bound to the context, to comply with ECMAScript 5");
     equal(Boundf().hello, "moe curly", "When called without the new operator, it's OK to be bound to the context");
-    ok(newBoundf instanceof F, "a bound instance is an instance of the original function");
   });
 
   test("bindAll", function() {

underscore.js

@@ -582,18 +582,10 @@
   // Delegates to **ECMAScript 5**'s native `Function.bind` if available.
   // We check for `func.bind` first, to fail fast when `func` is undefined.
   _.bind = function(func, context) {
-    var args, bound;
     if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
-    if (!_.isFunction(func)) throw new TypeError;
-    args = slice.call(arguments, 2);
-    return bound = function() {
-      if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments)));
-      ctor.prototype = func.prototype;
-      var self = new ctor;
-      ctor.prototype = null;
-      var result = func.apply(self, args.concat(slice.call(arguments)));
-      if (Object(result) === result) return result;
-      return self;
+    var args = slice.call(arguments, 2);
+    return function() {
+      return func.apply(context, args.concat(slice.call(arguments)));
     };
   };