Update nano and fix coreutils on Darwin (#15883)

* Fixed building coreutils on Darwin

* Bump nano version to 4.9

* Coreutils: Add program prefix g so we don't conflict with Apple utilities

* Fix intendation

* Make format more spack like

* Removed unnecesary changes

* Merge branch 'develop' of github.com:DiegoMagdaleno/spack into develop

Fix linking libgit2 on Darwin

* Revert "Merge pull request #3 from spack/develop"

This reverts commit 58dbbdb82bfa4aa689758971eb423ae2b9d2c293, reversing
changes made to dd7a413f4870fc2778f801c882a50cfade18fe97.

* Revert "Revert "Merge pull request #3 from spack/develop""

This reverts commit f956aa7b135c39ea0eb4ba6b9329714067098a7c.

* Revert "Merge branch 'develop' of github.com:DiegoMagdaleno/spack into develop"

This reverts commit 50321f798674ec30d5c62fe696b4f8bccef6ab3d.