Reversing SetLastError

kernel32!SetLastError(dwErrorCode)
{
    if(g_dwLastErrorToBreakOn!=null)
    {
         if(g_dwLastErrorToBreakOn==dwErrorCode)
        {
            DbgBreakPoint();
        }
    }
    if(teb.LastErrorValue!=dwErrorCode)
    {
        teb.LastErrorValue=dwErrorCode;
    }
}

kernel32!DbgBreakPoint:
7c87f4cb ff25e810807c jmp dword ptr [kernel32!_imp__DbgBreakPoint (7c8010e8)]

ntdll!DbgBreakPoint:
7c921230 cc               int     3