--- gcc/system.h.orig	2015-01-13 09:26:00.000000000 +0900
+++ gcc/system.h	2020-01-03 17:42:55.000000000 +0900
@@ -216,6 +216,7 @@
 
 #ifdef __cplusplus
 # include <algorithm>
+# include <map>
 # include <cstring>
 # include <utility>
 #endif