Use a per-CPU/thread private stack for machinery
Use C++ mangled name for `dynamic_wrapper_of`
Eschew DynamoRIO register names and use real ones
Switch stacks during interrupt handling

Known to be SMP unsafe. Nested entraces into the machinery require
proper handling too!
Use nestable private stack entry/exit helpers

Currently only works in userspace
Nested private stack entrances with chain linking
Use an empty operand when not mangling registers
Remove outdated and erroneous comments
Working on debugging a few things. Looks like qemus savevm console function was the killer feature for debugging granary's triple faults. Seems that kernel_get_cpu_state was being invoked somewhere where GS was NULL.