Create our own sys_siglist for systems without it for use by strsignal()

src/script.c

@@ -629,7 +629,6 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
 	}
 	flush_output(&output);
 
-#ifdef HAVE_STRSIGNAL
 	if (cstat->type == CMD_WSTATUS && WIFSIGNALED(cstat->val)) {
 	    int signo = WTERMSIG(cstat->val);
 	    if (signo && signo != SIGINT && signo != SIGPIPE) {
@@ -640,7 +639,6 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
 		write(STDOUT_FILENO, "\n", 1);
 	    }
 	}
-#endif
 	do {
 	    n = term_restore(script_fds[SFD_USERTTY], 0);
 	} while (!n && errno == EINTR);