[C++ PATCH] missed testcase

https://gcc.gnu.org/ml/gcc-patches/2018-10/msg02065.html
	* g++.dg/lookup/friend21.C: New.

From-SVN: r265697

gcc/testsuite/ChangeLog

+2018-10-31  Nathan Sidwell  <nathan@acm.org>
+
+	* g++.dg/lookup/friend21.C: New.
+
 2018-10-31  Martin Liska  <mliska@suse.cz>
 
 	PR driver/83193

gcc/testsuite/g++.dg/lookup/friend21.C

+// Unhiding a friend erroneously mutated a binding
+
+class X 
+{
+  friend void frob (int, int);
+};
+  
+void frob (int);
+void frob (int, int);
+
+void foo ()
+{
+  frob (1); // Only saw unhidden friend
+}