Editorial: AssignmentElement -> AssignmentRestElement (#700)

This was probably a copy/paste bug. This should refer to the production it
is defined in.

spec.html

@@ -13831,7 +13831,7 @@ <h1>Runtime Semantics: IteratorDestructuringAssignmentEvaluation</h1>
               1. Increment _n_ by 1.
           1. If |DestructuringAssignmentTarget| is neither an |ObjectLiteral| nor an |ArrayLiteral|, then
             1. Return ? PutValue(_lref_, _A_).
-          1. Let _nestedAssignmentPattern_ be the parse of the source text corresponding to |DestructuringAssignmentTarget| using either |AssignmentPattern[~Yield]| or |AssignmentPattern[+Yield]| as the goal symbol depending upon whether this |AssignmentElement| has the <sub>[Yield]</sub> parameter.
+          1. Let _nestedAssignmentPattern_ be the parse of the source text corresponding to |DestructuringAssignmentTarget| using either |AssignmentPattern[~Yield]| or |AssignmentPattern[+Yield]| as the goal symbol depending upon whether this |AssignmentRestElement| has the <sub>[Yield]</sub> parameter.
           1. Return the result of performing DestructuringAssignmentEvaluation of _nestedAssignmentPattern_ with _A_ as the argument.
         </emu-alg>
       </emu-clause>