c++/98032 - add testcase

This adds another testcase for PR95719.

2021-04-30  Richard Biener  <rguenther@suse.de>

	PR c++/98032
	* g++.dg/pr98032.C: New testcase.

gcc/testsuite/g++.dg/pr98032.C

@@ -0,0 +1,20 @@
+// { dg-do compile }
+
+namespace osl {
+class Thread {
+public:
+  virtual ~Thread();
+  virtual void join();
+};
+} // namespace osl
+class SimpleReferenceObject {
+protected:
+  virtual ~SimpleReferenceObject();
+};
+class Thread : SimpleReferenceObject, osl::Thread {
+public:
+  using osl::Thread::join;
+};
+class RenderThread : Thread {
+  RenderThread() { join(); }
+};