PSI2IR KT-49053 skip fake overrides with unresolved types in signature

compiler/testData/codegen/box/javaInterop/unresolvedJavaClassInDifferentFile.kt

@@ -0,0 +1,30 @@
+// TARGET_BACKEND: JVM
+
+// FILE: unresolvedJavaClassInDifferentFile.kt
+import j.Base
+
+class Derived : Base() {
+    fun ok() = "OK"
+}
+
+fun box() =
+    Derived().ok()
+
+// FILE: j/Foo.java
+package j;
+
+// NB package-private class 'j.Bar' in file 'j/Foo.java'
+class Bar {
+}
+
+// FILE: j/Base.java
+package j;
+
+public class Base {
+    protected Bar bar() {
+        return new Bar();
+    }
+
+    protected void bar(Bar b) {
+    }
+}