Migrate language block 46 - canonical_const ... char_escape.

tests/language_2/cha_deopt3_test.dart

Index: tests/language_2/cha_deopt3_test.dart
diff --git a/tests/language_strong/cha_deopt3_test.dart b/tests/language_2/cha_deopt3_test.dart
similarity index 83%
rename from tests/language_strong/cha_deopt3_test.dart
rename to tests/language_2/cha_deopt3_test.dart
index 64f986e687fcf3da765f68259fd737ec168a816f..dfcd7af96175562bb9f03bdf7fc484cc1e5480c3 100644
--- a/tests/language_strong/cha_deopt3_test.dart
+++ b/tests/language_2/cha_deopt3_test.dart
@@ -1,7 +1,8 @@
 // Copyright (c) 2014, 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.
-// VMOptions=--optimization-counter-threshold=100
+// VMOptions=--optimization-counter-threshold=100 --no-background-compilation
+// VMOptions=--optimization-counter-threshold=100 --no-background-compilation --no-use-field-guards
 
 // Test lazy deoptimization at type checks with interface implementation.