Remove special treatment of intersection types with await expressions…

… (it is in flatten now)

specification/dartLangSpec.tex

@@ -17111,12 +17111,8 @@ \subsection{Await Expressions}
 
 \LMHash{}%
 Evaluation of an await expression $a$ of the form \code{\AWAIT{} $e$}
-where $e$ has static type $S_0$ proceeds as follows:
+where $e$ has static type $S$ proceeds as follows:
 First, the expression $e$ is evaluated to an object $o$.
-If $S_0$ is of the form \code{$X$\,\,\&\,\,$S_1$}
-(\ref{intersectionTypes})
-then let $S$ be $X$.
-Otherwise, let $S$ be $S_0$.
 Let $T$ be \Flatten{$S$}
 (\ref{functionExpressions}).
 It is a dynamic type error if the run-time type of $o$ is not a subtype