Rename "inv_cse_licm.dart" to "inv_cse_licm_test.dart".

Without "_test.dart" in the name, the test runner will not actually
run it.

Change-Id: Ia4f8d33c6b294879909b0a838971df21cae4e67b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/127100
Reviewed-by: Teagan Strickland <sstrickl@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>

Author: munificent

tests/language_2/inv_cse_licm.dart renamed to tests/language_2/inv_cse_licm_test.dart

@@ -2,7 +2,7 @@
 // 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.
 
-// VMOptions=--deterministic--optimization_counter_threshold=10
+// VMOptions=--deterministic --optimization_counter_threshold=10
 
 import 'dart:typed_data';
 import "package:expect/expect.dart";