captured wildcards: refactor to extract same parts for extends/super wildcards, ensure upper bound is not lost for extends wildcard (IDEA-57292)

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

@@ -0,0 +1,24 @@
+
+class C56 {
+
+  class A<T,S extends T> {}
+
+  class C {
+    void foo(A<?,?> x){
+      bar(x);
+    }
+    <T,S extends T> void bar(A<T,S> x){}
+  }
+}
+
+class C57 {
+  class B<T,S> {}
+  class A<T,S extends T> extends B<T,S> {}
+
+  class C {
+    void foo(A<?,?> x){
+      bar(x);
+    }
+    <T,S extends T> void bar(B<T,S> x){}
+  }
+}