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

tests/language/exception_in_increment_test.dart

Index: tests/language/exception_in_increment_test.dart
diff --git a/tests/language/exception_in_increment_test.dart b/tests/language/exception_in_increment_test.dart
index a0537088eca8ca07d2e8e7e325e4e6b8759431c9..0aa3b1ea9d7f334ec5d57b124fb06cd7e785dbca 100644
--- a/tests/language/exception_in_increment_test.dart
+++ b/tests/language/exception_in_increment_test.dart
@@ -3,7 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 // Test throws exception in the middle of the increment operation, the setter
 // part of the instance field increment never completes.
-// VMOptions=--optimization-counter-threshold=10
+// VMOptions=--optimization-counter-threshold=10 --no-background-compilation
 
 main() {
   var a = new A();