2.1.23 [ECMA-262/7] Section 19.1.2.18 Object.setPrototypeOf ( O, proto )

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V0196: Object.setPrototypeOf throws an error immediately if parameter O is not an object

The specification states:

 ... Object.setPrototypeOf ( O, proto )
  
     When the setPrototypeOf function is called with arguments O and proto, the following 
     steps are taken:
  
          1.  Let O be ? RequireObjectCoercible(O).
          2.  If Type(proto) is neither Object nor Null, throw a TypeError exception.
          3.  If Type(O) is not Object, return O.
          4.  Let status be ? O.[[SetPrototypeOf]](proto).
          5.  If status is false, throw a TypeError exception.
          6.  Return O.

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ToObject(O) is done instead of RequireObjectCoercible(O) in step 1. As a result, Object.setPrototypeOf throws an error immediately if parameter O is not an object.