re PR c++/85076 (ICE with invalid template used as lambda argument)

	PR c++/85076
	* tree.c (cp_build_reference_type): If to_type is error_mark_node,
	return it right away.

	* g++.dg/cpp1y/pr85076.C: New test.

From-SVN: r258901

gcc/cp/ChangeLog

+2018-03-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/85076
+	* tree.c (cp_build_reference_type): If to_type is error_mark_node,
+	return it right away.
+
 2018-03-27  Volker Reichelt  <v.reichelt@netcologne.de>
 
 	* search.c (check_final_overrider): Use inform instead of error

gcc/cp/tree.c

@@ -1078,6 +1078,9 @@ cp_build_reference_type (tree to_type, bool rval)
 {
   tree lvalue_ref, t;
 
+  if (to_type == error_mark_node)
+    return error_mark_node;
+
   if (TREE_CODE (to_type) == REFERENCE_TYPE)
     {
       rval = rval && TYPE_REF_IS_RVALUE (to_type);

gcc/testsuite/ChangeLog

+2018-03-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/85076
+	* g++.dg/cpp1y/pr85076.C: New test.
+
 2018-03-27  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/85084

gcc/testsuite/g++.dg/cpp1y/pr85076.C

+// PR c++/85076
+// { dg-do compile { target c++14 } }
+
+template<typename> struct A*;	// { dg-error "expected unqualified-id before" }
+
+auto a = [](A<auto>) {};	// { dg-error "is not a template|has incomplete type" }