Add commentary to emphasize that new/const can be implicit, and new/const C<T>() is still an error when C<T> is super-bounded

Author: eernstg

specification/dartLangSpec.tex

@@ -7949,7 +7949,9 @@ \subsection{Super-Bounded Types}
   \commentary{%
     This includes the case where the actual type arguments have been provided
     by type inference, which is assumed to have taken place already
-    (\ref{typeInference}).%
+    (\ref{typeInference}).
+    It also includes the case where \NEW{} or \CONST{} is added implicitly
+    (\ref{unqualifiedInvocation}, \ref{functionExpressionInvocation}).%
   }
 \item $T$ occurs in the \synt{constructorDesignation} of
   a redirecting factory constructor header