Update rasta direct expectations.

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

 library test.mixin_library;
 import self as self;
 import "dart:core" as core;
 
 class Mixin<T extends core::Object> extends core::Object {
-  field dynamic x;
-  field dynamic y;
-  field dynamic z;
-  field self::Mixin::T t;
-  constructor •() → self::Mixin<self::Mixin::T>
-    : self::Mixin::x = self::f(), super core::Object::•();
+  field dynamic x = self::f();
+  field dynamic y = null;
+  field dynamic z = null;
+  field self::Mixin::T t = null;
+  constructor •() → void
+    : super core::Object::•()
+    ;
   method foo() → dynamic
-    return (throw core::_unresolvedSuperMethodError(this, #foo, <dynamic>[], <dynamic, dynamic>{}, null)).+(self::f());
+    return (throw new core::NoSuchMethodError::•(null, #foo, <dynamic>[], <dynamic, dynamic>{}, null)).+(self::f());
   method g(self::Mixin::T a) → self::Mixin::T
     return null;
   method h() → dynamic
     return self::V();
   method l() → dynamic
     return self::_private();
   method _privateMethod() → dynamic
     return 49;
   method publicMethod() → dynamic
     return this._privateMethod();
 }
 static method f() → dynamic
   return 2;
 static method V() → dynamic
   return 87;
 static method _private() → dynamic
   return 117;
 static method foo(dynamic m) → dynamic
   return m._privateMethod();