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

tests/language/inline_add_constants_to_initial_env_test.dart

Index: tests/language/inline_add_constants_to_initial_env_test.dart
diff --git a/tests/language/inline_add_constants_to_initial_env_test.dart b/tests/language/inline_add_constants_to_initial_env_test.dart
index 4417834b14b812475a7de1a1b07dac624cbc0c33..cd64f44af2ad1979d95f7c7338ddb83a1d00390c 100644
--- a/tests/language/inline_add_constants_to_initial_env_test.dart
+++ b/tests/language/inline_add_constants_to_initial_env_test.dart
@@ -3,7 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 // Test that SSA values are correctly numbered after inlining that adds
 // constants to original environment.
-// VMOptions=--optimization-counter-threshold=10
+// VMOptions=--optimization-counter-threshold=10 --no-background-compilation
 
 h(x, y) => x == y;