prussia_bios: Wrapping BIOS calls

[Ravenslofty]

Some open questions:

• Wrap all syscalls? (Even the undocumented ones)
• Wrap useful syscalls? (Nobody cares about _ExceptionEpilogue, right?)
• Implement it all in Rust? (as much as I'd like to, this might bloat executables a bit).

[Ravenslofty]

Syscalls by number (as documented in PS2tek):

• [ ] 0x01: ResetEE
• [x] 0x02: SetGsCrt - f5ea1b17
• [x] 0x04: Exit - f77ed8ff
• [ ] 0x05: _ExceptionEpilogue (useless?)
• [ ] 0x06: LoadExecPS2
• [ ] 0x07: ExecPS2
• [ ] 0x10: AddIntcHandler
• [ ] 0x11: RemoveIntcHandler
• [ ] 0x12: AddDmacHandler
• [ ] 0x13: RemoveDmacHandler
• [ ] 0x14: _EnableIntc
• [ ] 0x15: _DisableIntc
• [ ] 0x16: _EnableDmac
• [ ] 0x17: _DisableDmac
• [ ] 0x20: CreateThread
• [ ] 0x21: DeleteThread
• [ ] 0x22: StartThread
• [ ] 0x23: ExitThread
• [ ] 0x24: ExitDeleteThread
• [ ] 0x25: TerminateThread
• [ ] 0x26: iTerminateThread
• [ ] 0x29: ChangeThreadPriority
• [ ] 0x2A: iChangeThreadPriority
• [ ] 0x2B: RotateThreadReadyQueue
• [ ] 0x2C: _iRotateThreadReadyQueue
• [ ] 0x2D: ReleaseWaitThread
• [ ] 0x2E: iReleaseWaitThread
• [ ] 0x2F: GetThreadId
• [ ] 0x30/0x31: ReferThreadStatus/iReferThreadStatus
• [ ] 0x32: SleepThread
• [ ] 0x33: WakeupThread
• [ ] 0x34: iWakeupThread
• [ ] 0x35/0x36: CancelWakeupThread/iCancelWakeupThread
• [ ] 0x37/0x38: SuspendThread/iSuspendThread
• [ ] 0x39: ResumeThread
• [ ] 0x3A: iResumeThread
• [ ] 0x3B: JoinThread
• [ ] 0x3C: InitMainThread
• [ ] 0x3D: InitHeap
• [ ] 0x3E: EndOfHeap
• [ ] 0x40: CreateSema
• [ ] 0x41: DeleteSema
• [ ] 0x42: SignalSema
• [ ] 0x43: iSignalSema
• [ ] 0x44: WaitSema
• [ ] 0x45: PollSema
• [ ] 0x64: FlushCache
• [ ] 0x70: GsGetIMR
• [ ] 0x71: GsPutIMR
• [ ] 0x74: SetSyscall
• [ ] 0x78: SifSetDChain
• [ ] 0x7B: ExecOSD
• [ ] 0x7D: PSMode
• [ ] 0x7E: MachineType
• [ ] 0x7F: GetMemorySize