[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/rightElvisOperand.kt

@@ -0,0 +1,35 @@
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// IGNORE_BACKEND_FIR: JVM_IR
+// MODULE: lib
+// FILE: RightElvisOperand.java
+
+class RightElvisOperand {
+    static String foo() {
+        return null;
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+fun baz(): String? = null
+
+fun bar(): String = baz() ?: RightElvisOperand.foo()
+
+fun foo(x: String) {}
+
+fun box(): String {
+    try {
+        foo(baz() ?: RightElvisOperand.foo())
+        return "Fail: should have been an exception in `foo(baz() ?: RightElvisOperand.foo())`"
+    }
+    catch(e: NullPointerException) {}
+
+    try {
+        bar()
+        return "Fail: should have been an exception in `bar()`"
+    }
+    catch(e: NullPointerException) {
+        return "OK"
+    }
+}