new inference: initial tests

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/genericsHighlighting8/IDEA57557.java

@@ -0,0 +1,7 @@
+abstract class A {
+    abstract void foo(Enum<?> x);
+}
+
+class B extends A {
+    void foo(Enum<? extends Enum<?>> x) { }
+}