Change more Completion() to ? (bugfix)

In the Evaluation rule for
  UnaryExpression : `typeof` UnaryExpression
we have to unwrap the result of Evaluation
in order to make sense of step 2,
testing whether it's a Reference Record.

spec.html

@@ -19694,7 +19694,7 @@ <h1>The `typeof` Operator</h1>
         <h1>Runtime Semantics: Evaluation</h1>
         <emu-grammar>UnaryExpression : `typeof` UnaryExpression</emu-grammar>
         <emu-alg>
-          1. Let _val_ be Completion(Evaluation of |UnaryExpression|).
+          1. Let _val_ be ? Evaluation of |UnaryExpression|.
           1. If _val_ is a Reference Record, then
             1. If IsUnresolvableReference(_val_) is *true*, return *"undefined"*.
           1. Set _val_ to ? GetValue(_val_).