Update rasta outline expectations.

pkg/front_end/test/fasta/rasta/mixin_library.dart.outline.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::•();
+  constructor •() → void
+    ;
   method foo() → dynamic
-    return (throw core::_unresolvedSuperMethodError(this, #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();
+  ;