[bug#38606] [WIP v2 1/1] gnu: Add smlnj.

[Foo Chuan Wei]

> One particularly interesting issue of this package is, after retrieving
> a viable BOOTLIST file to use for compilation, we are left with this.
>
> --8<---------------cut here---------------start------------->8---
> brettg@oryx ~/Repos/smlnj [env]$ ./bin/.run/run.amd64-linux
> ./bin/.run/run.amd64-linux: Fatal error -- no in-core heap image found
> --8<---------------cut here---------------end--------------->8---
>
> Not quite sure how to investigate this issue. If anybody has any
> insights please share, otherwise I will just contact upstream in a the
> coming days.

For future reference:
It seems that this error can be avoided by deleting "PATH=/bin:/usr/bin"
from runtime/config/gen-posix-names.sh. In any case, /bin and /usr/bin
do not exist in Guix's build environment.