1.$is_desc64 r9, 10$
In this example, the descriptor pointed to by R9 is tested, and
if it is in 64-bit form, a branch to 10$ is taken.
2.$is_desc64 8(r0), 20$, size=quad
In this example, the quadword at 8(R0) is read, and the
descriptor it points to is tested. If it is in 64-bit form,
a branch to 20$ is taken.