Remove AggregateError.prototype.toString

spec.html

@@ -182,22 +182,6 @@ <h1>get _AggregateError_.prototype.errors</h1>
           1. Return ! CreateArrayFromList(_E_.[[AggregateErrors]]).
         </emu-alg>
       </emu-clause>
-
-      <emu-clause id="sec-aggregate-error.prototype.toString">
-        <h1>_AggregateError_.prototype.toString ( )</h1>
-        <p>The following steps are taken:</p>
-        <emu-alg>
-          1. Let _O_ be the *this* value.
-          1. If Type(_O_) is not Object, throw a *TypeError* exception.
-          1. Let _name_ be ? Get(_O_, `"name"`).
-          1. If _name_ is *undefined*, set _name_ to `"AggregateError"`; otherwise set _name_ to ? ToString(_name_).
-          1. Let _msg_ be ? Get(_O_, `"message"`).
-          1. If _msg_ is *undefined*, set _msg_ to the empty String; otherwise set _msg_ to ? ToString(_msg_).
-          1. If _name_ is the empty String, return _msg_.
-          1. If _msg_ is the empty String, return _name_.
-          1. Return the string-concatenation of _name_, the code unit 0x003A (COLON), the code unit 0x0020 (SPACE) and _msg_.
-        </emu-alg>
-      </emu-clause>
     </emu-clause>
 
     <emu-clause id="sec-properties-of-aggregate-error-instances">