Add property to __proto__ lead to TypeError.

[GSkachkov]

Some unexpected behavior during working with __proto__ property in JavaScriptCore. I did not reproduced in WebKit.
  
var f = function () {};
debug(f.__proto__.a); // undefined;
f.__proto__.a = 10;// TypeError:  undefined is not an object 
debug(f.__proto__ === Function.prototype); //true
Function.prototype.a = 10; //OK
debug(Function.prototype.a); // 10
debug(f.__proto__.a); // 10
var boo = function () {
    var foo = function ();
    foo.__proto__.b = 10;
    return foo.__proto__.b;
};
debug(boo());
var g = function () {
   f.__proto__.b = 101;
};
g();
debug(f.__proto__.b); // 10

[GSkachkov]

Possible somehow related to the https://bugs.webkit.org/attachment.cgi?id=270008&action=review

[Saam Barati]

Not sure. Can you try to see if this works before that revision? This behavior does indeed seem weird.

[GSkachkov]

It seems it was my broken build