[Test] Properly merge box against java testdata into codegen/box

Previous commit about it was 3199ce03 and it was completely wrong

compiler/testData/codegen/box/notNullAssertions/doGenerateParamAssertions.kt

@@ -0,0 +1,39 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// KOTLIN_CONFIGURATION_FLAGS: +JVM.DISABLE_CALL_ASSERTIONS
+// MODULE: lib
+// FILE: C.java
+package test;
+
+import org.jetbrains.annotations.NotNull;
+
+public abstract class C<Type> {
+
+    public abstract void doTest(@NotNull Type s);
+
+    public static void runTest(C a) {
+        try {
+            a.doTest(null);
+        } catch (NullPointerException e) {
+            return;
+        }
+        throw new AssertionError("Fail: NullPointerException expected");
+    }
+}
+
+// MODULE: main(lib)
+// FILE: B.kt
+import test.C
+
+class TestString : C<String>() {
+    override fun doTest(s: String) { }
+}
+
+class TestUnit : C<Unit>() {
+    override fun doTest(s: Unit) { }
+}
+
+fun box(): String {
+    C.runTest(TestString())
+    C.runTest(TestUnit())
+    return "OK"
+}