Suggested by Mark H Weaver <mhw@netris.org>.
* gnu/packages/patches/glibc-versioned-locpath.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/base.scm (glibc)[source]: Use it.
[arguments]: Add explicit version sub-directory to
libc_cv_localedir.
[native-search-paths]: Use 'GUIX_LOCPATH' instead of 'LOCPATH'.
(glibc-locales, glibc-utf8-locales): Write to a VERSION
sub-directory.