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

tests/language/vm/optimization_test.dart

Index: tests/language/vm/optimization_test.dart
diff --git a/tests/language/vm/optimization_test.dart b/tests/language/vm/optimization_test.dart
index 0b54b5e8a35193a9c616eec8a6998b0758c8af60..1dea3bd9b4b8bea4cbc874229c434b881afa4cac 100644
--- a/tests/language/vm/optimization_test.dart
+++ b/tests/language/vm/optimization_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.
 // Test various optimizations and deoptimizations of optimizing compiler..
-// VMOptions=--optimization-counter-threshold=10 --no-use-osr
+// VMOptions=--optimization-counter-threshold=10 --no-use-osr --no-background-compilation
 
 import "package:expect/expect.dart";