Update rasta direct expectations.

pkg/front_end/test/fasta/rasta/bad_explicit_super_constructor.dart.direct.expect

 library;
 import self as self;
 import "dart:core" as core;
 
 class A extends core::Object {
-  constructor •(dynamic x) → dynamic
+  constructor •(dynamic x) → void
     : super core::Object::•()
     ;
 }
 class B extends self::A {
-  const constructor •() → dynamic
+  const constructor •() → void
     : invalid-initializer
     ;
 }
 static method main() → dynamic {
   new self::B::•();
   const self::B::•();
 }