re PR c++/88187 (ICE on (invalid) C++ code when compiled with -std=c++17: Segmentation fault)

	PR c++/88187
	* decl.c (grokdeclarator): Don't diagnose deduction guide errors
	if !funcdecl_p.

	* g++.dg/other/pr88187.C: New test.

From-SVN: r266537

gcc/cp/ChangeLog

 2018-11-27  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/88187
+	* decl.c (grokdeclarator): Don't diagnose deduction guide errors
+	if !funcdecl_p.
+
 	PR c++/88181
 	* class.c (fixup_attribute_variants): Also propagate TYPE_PACKED
 	to variants.

gcc/cp/decl.c

@@ -11276,7 +11276,7 @@ grokdeclarator (const cp_declarator *declarator,
 		    if (!tmpl)
 		      if (tree late_auto = type_uses_auto (late_return_type))
 			tmpl = CLASS_PLACEHOLDER_TEMPLATE (late_auto);
-		    if (tmpl)
+		    if (tmpl && funcdecl_p)
 		      {
 			if (!dguide_name_p (unqualified_id))
 			  {

gcc/testsuite/ChangeLog

 2018-11-27  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/88187
+	* g++.dg/other/pr88187.C: New test.
+
 	PR c++/88181
 	* g++.dg/debug/pr88181.C: New test.
 

gcc/testsuite/g++.dg/other/pr88187.C

+// PR c++/88187
+// { dg-do compile }
+
+template <int> struct A;
+void f (A ());	// { dg-error "variable or field 'f' declared void" "" { target c++14_down } }
+		// { dg-error "missing template arguments before '\\(' token" "" { target c++14_down } .-1 }
+		// { dg-error "'auto' parameter not permitted in this context" "" { target c++17 } .-2 }