generics: do not prefer type with more bounds when additional bounds are just subtypes of the rest, discard unchecked conversion (IDEA-67669)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/AmbiguousMethodCallIDEA67669.java

@@ -0,0 +1,17 @@
+import java.util.Collection;
+import java.util.List;
+
+interface A
+{
+    <S extends Collection<?> & List<?>> void foo(S x);
+    <S extends List> String foo(S x);
+}
+
+
+class B
+{
+    public static void main(String[] args) {
+        A a = null;
+        char c = a.foo(null).<error descr="Cannot resolve method 'charAt(int)'">charAt</error>(0);
+    }
+}