Check for raise and supply if needed.

configure.ac

@@ -1744,6 +1744,7 @@ AC_CHECK_FUNCS([ \
 	poll \
 	prctl \
 	pstat \
+	raise \
 	readpassphrase \
 	reallocarray \
 	recvmsg \

openbsd-compat/bsd-misc.c

@@ -290,3 +290,11 @@ bzero(void *b, size_t n)
 	(void)memset(b, 0, n);
 }
 #endif
+
+#ifndef HAVE_RAISE
+int
+raise(int sig)
+{
+	kill(getpid(), sig);
+}
+#endif

openbsd-compat/bsd-misc.h

@@ -137,4 +137,8 @@ long long llabs(long long);
 void bzero(void *, size_t);
 #endif
 
+#ifndef HAVE_RAISE
+int raise(int);
+#endif
+
 #endif /* _BSD_MISC_H */