K1/K2: add test confirming the work of KT-54487 case

#KT-54487 Obsolete
#KT-63350 Declined

compiler/testData/codegen/box/fir/publicMethodCallViaPackagePrivateCommon.kt

@@ -0,0 +1,47 @@
+// TARGET_BACKEND: JVM_IR
+// ISSUE: KT-54487, KT-63350
+// FILE: p/I.java
+
+package p;
+
+public interface I {
+    String foo();
+}
+
+// FILE: p/I2.java
+
+package p;
+
+public interface I2 extends I {}
+
+// FILE: p/C.java
+
+package p;
+
+public class C {
+    static class Impl implements I {
+        public String foo() {
+            return "OK";
+        }
+    }
+
+    static class C1Base extends Impl {}
+    static class C2Base extends Impl {}
+
+    public static class C1 extends C1Base implements I2 {}
+    public static class C2 extends C2Base implements I2 {}
+
+    public static final C1 c1 = new C1();
+    public static final C2 c2 = new C2();
+}
+
+// FILE: test.kt
+
+import p.C
+
+fun <T> union(a: T, b: T) = a
+
+fun box() =
+// receiver type = I2 & C.Impl
+// method resolved to C.Impl.foo, but in backend IR the resulting call is I2.foo
+    union(C.c1, C.c2).foo()