Avoid cycle with F-bounded inner Java class

Fixes #13336.

Author: smarter

compiler/src/dotty/tools/dotc/core/classfile/ClassfileParser.scala

@@ -1061,6 +1061,8 @@ class ClassfileParser(
           }
         else if (sym == classRoot.symbol)
           instanceScope.lookup(name)
+        else if (sym == classRoot.symbol.owner && name == classRoot.name)
+          classRoot.symbol
         else
           sym.info.member(name).symbol
 

tests/pos-java-interop-separate/inner-fbounds/Configurer_1.java

@@ -0,0 +1,8 @@
+abstract class AbstractConfigurer {
+    abstract class AbstractRegistry<R extends AbstractRegistry<R>> {}
+}
+
+public final class Configurer_1 extends AbstractConfigurer {
+    public final class Registry extends AbstractRegistry<Registry> {}
+    public Registry registry() { return null; }
+}

tests/pos-java-interop-separate/inner-fbounds/Test_2.scala

@@ -0,0 +1,2 @@
+object Test:
+  def registry(cfg: Configurer_1) = cfg.registry