a) 64-bit switch_to scheduler macro (by Aravindh Puthiyaparambil)
b) implements 64-bit hypervisor_callback
c) fixes thread creation issues (thread_starter used to perform
initialisation)
Signed-off-by: Grzegorz Milos <gm281@cam.ac.uk>
to simplify the porting. 64 bit version of Mini-os now compiles, but does not work
because of the pagetables and some bits of scheduler not being written.
Signed-off-by: Grzegorz Milos <gm281@cam.ac.uk>