This removes the broken wine version of atexit and onexit. It keeps only dllonexit, which is implemented properly. The previous __call_atexit is moved to where the mingw onexit/atexit code is and adjusts it to work with the existing code. A call to __call_atexit is added in __tmainCRTStartup after the main function was called.
The code is mostly unchanged. This includes the following changes:
* Move all wine code to crt/wine to keep it separated from our own code
* Add a minimal winternl.h
* Remove the asm macros from wine/config.h
* Include wine/asm.h where required
* Fix the names of the exported functions (GCC uses thiscall now and no wrappers are used anymore)
Clang-CL does not support #pragma function like CL. The alternative to this approach is to disable all intrinsics for this single source file, but that is not trivial to do, as it can only be done by removing a compiler switch, which we have no CMake support for. Therefore this solution is simpler and as good.
