[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/inference/immutableArrayList.fir.kt

@@ -0,0 +1,17 @@
+// FILE: p/J.java
+package p;
+
+public interface J {
+    public interface Super<T> {}
+    public interface Sub<T> extends Super<T> {}
+}
+
+// FILE: k.kt
+
+import p.J.*
+
+class Foo<T>: Sub<T> {
+    fun foo(): Super<T> {
+        return Foo()
+    }
+}