generics: do not prefer interface over super class even if return type is more specific (IDEA-110568)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/genericsHighlighting/IDEA110568.java

@@ -0,0 +1,20 @@
+import java.util.Collection;
+
+public class IncorrectError extends NarrowClass {
+    public Collection<String> bar() {
+        return super.doStuff();
+    }
+}
+
+interface Interface {
+    Collection<String> doStuff();
+}
+
+class NarrowClass extends BaseClass implements Interface {
+}
+
+class BaseClass {
+    public Collection doStuff() {
+        return null;
+    }
+}