Allow S->T <: dynamic->T

test/dart_codegen/expect/types.txt

Index: test/dart_codegen/expect/types.txt
diff --git a/test/dart_codegen/expect/types.txt b/test/dart_codegen/expect/types.txt
index 11c859096e1ff436ff47f3b2107f6be5f5072c3e..f0ef1553ae7204fea25c32b9d33cf3b1213ed69d 100644
--- a/test/dart_codegen/expect/types.txt
+++ b/test/dart_codegen/expect/types.txt
@@ -5,15 +5,9 @@ info: line 10, column 6 of test/dart_codegen/types/c.dart: [DownCast] f4(3) (dyn
 warning: line 11, column 6 of test/dart_codegen/types/c.dart: [ClosureWrap] f4 ((dynamic) → dynamic) will need to be wrapped with a closure of type (A) → A
   f1(f4);
      ^^
-warning: line 12, column 6 of test/dart_codegen/types/c.dart: [ClosureWrap] f3 ((A) → A) will need to be wrapped with a closure of type (dynamic) → dynamic
-  f2(f3);
-     ^^
 info: line 10, column 14 of test/dart_codegen/types/d.dart: [DownCast] f4("""hello""") (dynamic) will need runtime check to cast to type A
   var x = f3(f4("""hello"""));
              ^^^^^^^^^^^^^^^
 warning: line 11, column 14 of test/dart_codegen/types/d.dart: [ClosureWrap] f4 ((dynamic) → dynamic) will need to be wrapped with a closure of type (A) → A
   var y = f1(f4);
              ^^
-warning: line 12, column 14 of test/dart_codegen/types/d.dart: [ClosureWrap] f3 ((A) → A) will need to be wrapped with a closure of type (dynamic) → dynamic
-  var z = f2(f3);
-             ^^