make a small dll for handling the msabi<->sysv adapter, using only assembly (taken from generated optimized rustc output) and handcrafted unwind information (c# exceptions in a callback seem to work fine in testing)
additionally, allow floating point arguments. this really only needs to occur on the c# side. msabi and sysv agree on the first 4 floating point args and for returns, so no work actually has to be done adapting these
with assembly being used, we can guarantee rax will not be stomped by compiler whims (and avoid potential floating point args from being trashed)
CasualPokePlayer