diff -pur a/gcc/system.h b/gcc/system.h
--- a/gcc/system.h	2015-01-05 13:33:28.000000000 +0100
+++ b/gcc/system.h	2017-09-03 18:28:15.000000000 +0200
@@ -216,6 +216,7 @@ extern int errno;
 
 #ifdef __cplusplus
 # include <algorithm>
+# include <map>
 # include <cstring>
 # include <utility>
 #endif