This patch is taken from debian's glibc package (generate-supported.mk).
It install the localedata/SUPPORTED file of the glibc. This file lists
all the supported locales of the glibc.

diff --git a/localedata/Makefile.old b/localedata/Makefile
index 34877c0..a61d9b9 100644
--- a/localedata/Makefile.old
+++ b/localedata/Makefile
@@ -91,7 +91,8 @@ endif
 # Files to install.
 install-others := $(addprefix $(inst_i18ndir)/, \
 			      $(addsuffix .gz, $(charmaps)) \
-			      $(locales))
+			      $(locales)) \
+                   $(inst_i18ndir)/SUPPORTED
 
 tests: $(objdir)/iconvdata/gconv-modules
 
@@ -195,6 +196,14 @@ endif
 
 include SUPPORTED
 
+$(inst_i18ndir)/SUPPORTED: SUPPORTED $(+force)
+	for locale in $(SUPPORTED-LOCALES); do \
+		[ $$locale = true ] && continue; \
+		echo $$locale | sed 's,/, ,' >> LOCALES; \
+	done
+	$(make-target-directory)
+	$(INSTALL_DATA) LOCALES $@
+
 INSTALL-SUPPORTED-LOCALES=$(addprefix install-, $(SUPPORTED-LOCALES))
 
 # Sometimes the whole collection of locale files should be installed.
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<tr><td><span title='2019-12-08 00:47:26 +0100'>2019-12-08</span></td><td><a href='/guix/commit/gnu/machine?id=a1d7920861a8d6c6774149eaf939eb2636942090'>machine: Remove unnecessary record self-referencing bindings.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-12-07 00:29:10 +0100'>2019-12-07</span></td><td><a href='/guix/commit/gnu/machine?id=2617d956d8ae122128a1ba2cc74983cbd683b042'>machine: ssh: Deprecate missing 'host-key' field.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-12-04 18:16:08 +0100'>2019-12-04</span></td><td><a href='/guix/commit/gnu/machine?id=ed15dfcf31ec35c58f5a44d1d8adf5048da67ea6'>machine: ssh: &lt;machine-ssh-configuration&gt; can include the host key.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-10-22 18:32:52 +0200'>2019-10-22</span></td><td><a href='/guix/commit/gnu/machine?id=c93994b5e43acc6048b81836d30632e015306c92'>machine: digital-ocean: Rename 'enable-ipv6' to 'enable-ipv6?'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-10-22 18:32:52 +0200'>2019-10-22</span></td><td><a href='/guix/commit/gnu/machine?id=12712817ae97eb6305deeaad68ce17c9fa212917'>machine: Implement 'digital-ocean-environment-type'.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-17 20:45:13 +0800'>2019-08-17</span></td><td><a href='/guix/commit/gnu/machine?id=02460db0474ff5ac0d867ed6d5b192c062af0abc'>machine: ssh: Fix sanity checks.</a><span class='msg-avail'>...</span></td><td>宋文武</td></tr>
<tr><td><span title='2019-08-16 08:47:28 -0400'>2019-08-16</span></td><td><a href='/guix/commit/gnu/machine?id=4cc5e5204b503afb4536a1e93e2fd7a9f57f12bf'>machine: Use 'become-command'.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-15 07:43:13 -0400'>2019-08-15</span></td><td><a href='/guix/commit/gnu/machine?id=3033d59ac9a747b42a1fa6ca6664d4fbc62ca117'>machine: Automatically authorize the coordinator's signing key.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-15 07:43:09 -0400'>2019-08-15</span></td><td><a href='/guix/commit/gnu/machine?id=9c70c460a05b2bc60f3f3602f0a2dba0f79ce86c'>machine: Implement 'roll-back-machine'.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-15 07:43:03 -0400'>2019-08-15</span></td><td><a href='/guix/commit/gnu/machine?id=5ea7537b9a650cfa525401c19879080a9cf42e13'>machine: Allow non-root users to deploy.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-14 15:38:09 -0400'>2019-08-14</span></td><td><a href='/guix/commit/gnu/machine?id=2c8e04f13670c8c7ad8c7195c305960dd1905363'>remote: Build derivations appropriate for the remote's</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-07 18:29:07 -0400'>2019-08-07</span></td><td><a href='/guix/commit/gnu/machine?id=d84e9b75b2aba98583531f2876d9298871389585'>machine: Add 'build-locally?' field for managed hosts.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-06 16:40:25 -0400'>2019-08-06</span></td><td><a href='/guix/commit/gnu/machine?id=fd3119db4fed02a1f3491460be776a3b5d2b2cd3'>machine: Implement safety checks.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-08-06 15:48:51 -0400'>2019-08-06</span></td><td><a href='/guix/commit/gnu/machine?id=d97ce20400b5d2967bfbc0e9fbfb99bbb2daed4f'>machine: Rename 'system' field.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-07-26 19:19:49 +0200'>2019-07-26</span></td><td><a href='/guix/commit/gnu/machine?id=5c793753b31b1dcd9a554bce953124f7ae88ca9a'>guix system: Add 'reconfigure' module.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-07-18 12:57:00 +0200'>2019-07-18</span></td><td><a href='/guix/commit/gnu/machine?id=53f21b3fe9ed57f0feef003185b561efc9b3e30c'>machine: Fix typo.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-07-06 02:10:04 -0400'>2019-07-06</span></td><td><a href='/guix/commit/gnu/machine?id=fa9edf09e992db7510c7471486dffc93e1e707e5'>gnu: Add machine type for deployment specifications.</a><span class='msg-avail'>...</span></td><td>Jakob L. Kreuze</td></tr>