add test which reproduces the problem

idea/testData/kdoc/finder/OverriddenWithSubstitutedType.kt

@@ -0,0 +1,10 @@
+open class Foo<T>() {
+    /**
+     * Doc for method xyzzy
+     */
+    open fun xyzzy(): Int = 0
+}
+
+open class Bar(): Foo<String>() {
+    override fun xyzzy(): Int = 1
+}