[PR c++/84694] ICE on template friend decl

https://gcc.gnu.org/ml/gcc-patches/2018-03/msg00221.html
	PR c++/84694
	* friend.c (do_friend): Restore check for identifier_p inside
	TEMPLATE_ID_EXPR.

	PR c++/84694
	* g++.dg/template/pr84694.C: New.

From-SVN: r258254

gcc/cp/ChangeLog

+2018-03-05  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/84694
+	* friend.c (do_friend): Restore check for identifier_p inside
+	TEMPLATE_ID_EXPR.
+
 2018-03-05  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/84618

gcc/cp/friend.c

@@ -495,7 +495,8 @@ do_friend (tree ctype, tree declarator, tree decl,
   if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
     {
       declarator = TREE_OPERAND (declarator, 0);
-      declarator = OVL_NAME (declarator);
+      if (!identifier_p (declarator))
+	declarator = OVL_NAME (declarator);
     }
 
   if (ctype)

gcc/testsuite/ChangeLog

+2018-03-05  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/84694
+	* g++.dg/template/pr84694.C: New.
+
 2018-03-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/84524

gcc/testsuite/g++.dg/template/pr84694.C

+// PR c++84694 ICE on friend decl
+template<typename>
+struct a {
+  template<int ()> void b();
+  friend void b<0>(); // ICEd with useless friend decl
+};