Due to the way this syscall handles siginfo_t, we only need to shift
data through the padding.
This is due to the syscall not allowing you to send siginfo_t with
si_code being positive. Which is what the kernel uses to interpret the
data if it is reinterpreting it.
This isn't quite a 100% clean sweep of IWYU.
There are some false positives where clang fails.
Additionally there are still a few missed in the frontend side of things
that I didn't get to
The vast majoirty of syscalls don't need anything in thread or frame.
So lets save an indirection for all those syscalls.
Most of the syscalls which do need Thread (or CTX via
Thread are in Thread.cpp or Memory.cpp
These have all been modifiy to fetch Thread from Frame