Move kernel baseline tests to front_end.

pkg/kernel/testcases/input/stringliteral.dart

Index: pkg/kernel/testcases/input/stringliteral.dart
diff --git a/pkg/kernel/testcases/input/stringliteral.dart b/pkg/kernel/testcases/input/stringliteral.dart
deleted file mode 100644
index 8e64de25ed1eb1e63133d44258ede8c9a2bd5ae0..0000000000000000000000000000000000000000
--- a/pkg/kernel/testcases/input/stringliteral.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-var color = 'brown';
-var thing = 'lazy dog';
-var phrase = "The quick $color fox\njumped over the $thing.\n";
-var adjacent = '$color$color$color';
-var linebreaks = '$color\n$color\n$color';
-var other = '$color\n is \n$color';
-
-main() {}