The 'glibc-supported-locales.patch' was updated for glibc 2.29, breaking
compatibility with 2.27. Add a 2.27-specific supported locales patch.
* gnu/packages/patches/glibc-2.27-supported-locales.patch: New file.
* gnu/packages/base.scm (glibc-2.27)[source](patches): Use
'glibc-2.27-supported-locales.patch' instead.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
