* Remove global variable from aarch64 tcg target
This obviously breaks trying to run two unicorn instances at once on
aarch64. It appears a similar variable had already been moved to the
state struct for i386 tcg target.
* Reenable writing to jit region while calling tb_add_jump
On arm macs, every place that writes to jit code needs to have
tb_exec_unlock called first. This is already in most necessary places,
but not this one.
* Don't forget to call restore_jit_state in uc_context_restore
Every time UC_INIT is used, restore_jit_state must be used on the return
path, or occasional assertion failures will pop up on arm macs.
* Restore pc before calling into tlb fill hook
In my application it is important to have correct pc values available
from this hook.
