For PR 292146: mksh segfaults on 16-CURRENT.

--- Build.sh	2020-09-05 00:02:04.000000000 +0300
+++ Build.sh.new	2026-01-06 12:05:33.268065000 +0200
@@ -26,6 +26,11 @@
 #
 # Used environment documentation is at the end of this file.
 
+HAVE_SYS_SIGNAME=0 
+HAVE__SYS_SIGNAME=0 
+HAVE_SYS_SIGLIST=0 
+HAVE__SYS_SIGLIST=0
+
 LC_ALL=C; LANGUAGE=C
 export LC_ALL; unset LANGUAGE
 
--- histrap.c	2020-10-02 01:53:47.000000000 +0300
+++ histrap.c.new	2026-01-06 12:05:40.049235000 +0200
@@ -1106,7 +1106,8 @@
 #if HAVE_SYS_SIGLIST
 		sigtraps[i].mess = sys_siglist[i];
 #elif HAVE_STRSIGNAL
-		sigtraps[i].mess = strsignal(i);
+		//sigtraps[i].mess = strsignal(i);
+		 strdupx(sigtraps[i].mess, strsignal(i), APERM);
 #else
 		sigtraps[i].mess = NULL;
 #endif