Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c	(revision 203626)
+++ gcc/c-family/c-common.c	(working copy)
@@ -240,7 +240,7 @@ int flag_use_repository;
 
 /* The C++ dialect being used. C++11 is the default.  */
 
-enum cxx_dialect cxx_dialect = cxx1y;
+enum cxx_dialect cxx_dialect = cxx11;
 
 /* Maximum template instantiation depth.  This limit exists to limit the
    time it takes to notice excessively recursive template instantiations.
Index: gcc/cp/constraint.cc
===================================================================
--- gcc/cp/constraint.cc	(revision 203826)
+++ gcc/cp/constraint.cc	(working copy)
@@ -786,6 +786,8 @@ finish_constexpr_expr (tree expr)
 void
 check_constrained_friend (tree fn, tree reqs)
 {
+  if (fn == error_mark_node)
+    return;
   gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
 
   // If there are not constraints, this cannot be an error.