Correct dynamic type of tear-off with covariant parameter

specification/dartLangSpec.tex

@@ -15244,7 +15244,7 @@ \subsubsection{Instance Method Closurization}
 \LMHash{}%
 For each parameter $p_j$, $j \in 1 .. n+k$, if $p_j$ is covariant
 (\ref{covariantParameters})
-then $T_j$ is the built-in class \code{Object}.
+then $T_j$ is \DYNAMIC. %% No user code will see this, avoid downcast in body.
 
 \commentary{%
 This is concerned with the dynamic type of the function object obtained by
@@ -15257,7 +15257,7 @@ \subsubsection{Instance Method Closurization}
 }
 
 \LMHash{}%
-If $T$ is a non-generic class then for $j \in 1 .. n+k$,
+Otherwise, if $T$ is a non-generic class then for $j \in 1 .. n+k$,
 $T_j$ is a type annotation that denotes the same type
 (\ref{typeType})
 as that which is denoted by the type annotation on
@@ -15400,7 +15400,7 @@ \subsubsection{Super Closurization}
 \LMHash{}%
 For each parameter $p_j$, $j \in 1 .. n+k$, if $p_j$ is covariant
 (\ref{covariantParameters})
-then $T_j$ is the built-in class \code{Object}.
+then $T_j$ is \DYNAMIC.
 
 \commentary{%
 This is concerned with the dynamic type of the function object obtained by
@@ -15413,7 +15413,7 @@ \subsubsection{Super Closurization}
 }
 
 \LMHash{}%
-If $S$ is a non-generic class then for $j \in 1 .. n+k$,
+Otherwise, if $S$ is a non-generic class then for $j \in 1 .. n+k$,
 $T_j$ is a type annotation that denotes the same type
 (\ref{typeType})
 as that which is denoted by the type annotation on