* gnu/packages/bash.scm (bash-completion): Update to 2.3.
* gnu/packages/patches/bash-completion-directories.patch: New version of
the patch for the same purpose.
* gnu/packages/patches/bash-completion-directories.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/bash.scm (bash-completion)[source]: Use it.