This PR introduces a new macro, DETOUR_CUSTOM_STATIC2, to unify detour declarations
across different platforms and Source Engine versions, improving code readability.
- Linux i386 (TF2) → uses __attribute__((regparm(2)))
- Windows (CSGO) → uses __fastcall
- All other platforms → falls back to standard DETOUR_DECL_STATIC2
By consolidating detour declarations into a single macro, code is easier to read,
maintain, and less error-prone across different platforms and ABIs.