I only know of two operating systems where IP address parsing (and the address resolver in general) is part of the TCP/IP stack: ITS and z/OS. MS-DOS gets an honorable mention due to not having any architectural distinction between parts of the system at all, and z/OS only qualifies because it's not entirely clear where the boundaries of the "TCP/IP stack" are to begin with. (One would be forgiven for thinking that the TCP/IP stack is contained in the address space called "TCPIP". However, significant parts of it are in the LPA, which is part of every address space, and it's not clear to me yet where exactly the resolver is.)