Move kernel baseline tests to front_end.

pkg/front_end/testcases/rasta/class_hierarchy.dart.dartk.expect

 library;
 import self as self;
 import "dart:core" as core;
 
 class A extends core::Object {
   constructor •() → self::A
     : invalid-initializer;
 }
 class B extends core::Object {
   constructor •() → self::B
     : invalid-initializer;
 }
 class C extends core::Object {
   constructor •() → dynamic
     : invalid-initializer;
 }
 class D extends core::Object {
   static factory •() → self::D
     invalid-statement;
 }
 static method main() → void {
   new self::A::•();
   new self::B::•();
   new self::C::•();
   invalid-expression.call();
 }