Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/rasta/unresolved_constructor.dart.dartk.expect

-library;
-import self as self;
-import "dart:core" as core;
-
-class Foo extends core::Object {
-  constructor •(dynamic x, dynamic y) → dynamic
-    : super core::Object::•()
-    ;
-}
-static method main() → dynamic {
-  invalid-expression;
-  throw core::_unresolvedConstructorError(self::Foo, #Foo.notHere, <dynamic>[], <dynamic, dynamic>{}, null);
-}