linuxulator: add stub arm64 linux_genassym.c

This will be fleshed out in the future but allows us to build the arm64
linuxulator using the same infrastructure as x86.

diff --git a/sys/arm64/linux/linux_genassym.c b/sys/arm64/linux/linux_genassym.c
new file mode 100644 (file)
index 0000000..661f8c9
--- /dev/null
+++ b/sys/arm64/linux/linux_genassym.c
@@ -0,0 +1,2 @@
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");