Kill blackBoxFile()

If your test is supposed to use blackBoxFile(), maybe it should be placed into
box/boxWithStdlib directory

compiler/testData/codegen/notNullAssertions/doGenerateParamAssertions.java

@@ -6,12 +6,12 @@ public abstract class doGenerateParamAssertions {
 
     public abstract void bar(@NotNull String s);
     
-    public static String foo(doGenerateParamAssertions a) {
+    public static void foo(doGenerateParamAssertions a) {
         try {
             a.bar(null);
         } catch (IllegalArgumentException e) {
-            return "OK";
+            return;
         }
-        return "Fail: AssertionError expected";
+        throw new AssertionError("Fail: IllegalArgumentException expected");
     }
 }