* guix/build/bournish.scm (%bournish-language): Add a joiner to SCHEME.
Compile only to Scheme.
* tests/bournish.scm: New file.
* Makefile.am (SCM_TESTS): Add it.
* guix/build/bournish.scm: New file.
* Makefile.am (MODULES): Add it.
* gnu/system/linux-initrd.scm (base-initrd): Add (guix build bournish)
and use it.