ntdll: Add %gs support for FreeBSD.
diff --git a/configure b/configure
index fe69a20..54573a4 100755
--- a/configure
+++ b/configure
@@ -5837,6 +5837,7 @@
 	machine/cpu.h \
 	machine/limits.h \
 	machine/soundcard.h \
+	machine/sysarch.h \
 	mntent.h \
 	mpg123.h \
 	ncurses.h \