2.1.66 [ECMA-262/6] Section 19.1.3.4 Object.prototype.propertyIsEnumerable ( V )

V0133: Object.prototype.propertyIsEnumerable throws a TypeError if its argument is a symbol

The specification states:

 19.1.3.4 Object.prototype.propertyIsEnumerable ( V )
  
     When the propertyIsEnumerable method is called with argument V, the following steps 
     are taken:
         1.  Let P be ToPropertyKey(V).
         2.  ReturnIfAbrupt(P).
         3.  Let O be ToObject(this value).
         4.  ReturnIfAbrupt(O).
         5.  Let desc be O.[[GetOwnProperty]](P).
         6.  ReturnIfAbrupt(desc).
         7.  If desc is undefined, return false.
         8.  Return the value of desc.[[Enumerable]].

IE11 Mode (All versions)

In step 1, ToString(V) is invoked instead of ToPropertyKey(V). The result is that a TypeError is thrown if V is a symbol or if an error occurs in coercing V to a string.