Add missing musl arch specific setjmp.h file

Signed-off-by: Simon Davies <simongdavies@users.noreply.github.com>

Author: simongdavies

src/hyperlight_guest/third_party/musl/arch/x86_64/bits/setjmp.h

@@ -0,0 +1 @@
+typedef unsigned long __jmp_buf[8];