This gets us everything we need (I hope!) to support 16-bit code in LX
binaries and call into 16-bit OS/2 APIs. This is just enough to call
into VioGetMode() (which isn't otherwise implemented yet) as an example.
If this is ever used Winelib-style to provide an OS/2 API to native Linux
binaries, the 16-bit system APIs are 32-bit clean and C callable, as one
might expect them to be. All the tapdancing is to support existing LX
binaries in the loader and bridge between the 32-bit clean APIs and
existing 16-bit code that expects to call 16-bit APIs.
This was a staggering amount of effort, but yay!
Other fixes and improvements probably leaked into this commit, as a
lot of code got touched and a lot of research and debugging took place.
Ryan C. Gordon