this platform doesn't provide strtoul(), and zsh has no compat.c
replacement.  the patch (attached) provides one from NetBSD sources
(which i believe has a liberal enough license to be included in zsh).

there are two remaining problems, but i have no idea where to start
on either of them:

 + unless compiled with --disable-dynamic, any attempt to use
   completion-related features crashes the shell with 'Undefined
   symbol: _incompfunc'

 + job control doesn't work properly.  while typing ^Z in 'vi'
   works fine, in 'vim', the program immediately resumes, rather
   than returning to the shell.  both work fine with the system
   'csh'.

        - river.