Add --no-background-compilation to tests that expect to run code in optimized form

tests/language/constant_string_interpolation_test.dart

Index: tests/language/constant_string_interpolation_test.dart
diff --git a/tests/language/constant_string_interpolation_test.dart b/tests/language/constant_string_interpolation_test.dart
index 0a8a81ce1a8ea0d70714f85fca497fa77a80d447..bc301252ba7902bdc9e7ffe24c6692e870f973fc 100644
--- a/tests/language/constant_string_interpolation_test.dart
+++ b/tests/language/constant_string_interpolation_test.dart
@@ -1,7 +1,7 @@
 // Copyright (c) 2013, 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=10 --no-use-osr
+// VMOptions=--optimization-counter-threshold=10 --no-use-osr --no-background-compilation
 
 import "package:expect/expect.dart";