Also assume that all register functions are stdcall.

Saves some space by not having unused entries is the arrays tracking these
states.

Ddraw and d3d8 already translate half of them, it turns out the lookup
table actually saves lines there.

Also fix the compiler warnings introduced by this change.

This improves the Win64 compatibility.

Fix also the compiler warnings introduced by this change.

wininet/tests: INTERNET_STATUS_CLOSING_CONNECTION and  ..._CONNECTION_CLOSED callbacks can appear after ..._REQUEST_COMPLETE.