As we are moving more and more OS specific code to the frontend, this is
another set of functions that can be moved to FEXLoader from FEXCore.
No functional change here, only code moved from protected to private and
to FEXLoader's SignalDelegator.
Once more thread handling is moved to the frontend we can move even more
out of FEXCore. As follows:
- CheckXIDHandler can get moved.
- First pthread FEX makes would just call this.
- Register/UnregisterTLSState
- This can happen in the clone/thread handler once the frontend
handles it.
This leaves very little in the backend and is mostly an interface for
passing signal data to the frontend that it needs once a signal has
occured.
It additionally also is used for `SignalThread`.
Moves the dummy handlers over to this library. This will end up getting
used for more than the mingw test harness runner once the instruction
count CI is operational.
Ryan Houdek