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='2023-05-25 09:45:02 +0100'>2023-05-25</span></td><td><a href='/guix/commit/gnu/packages/valgrind.scm?id=e5184ba4349a66db24c5723c5a29befca6bcd338'>gnu: valgrind: Mark as not supported for armhf-linux.</a><span class='msg-avail'>...<span class='msg-tooltip'>From the build log:
  checking for a supported CPU... no (arm)
  configure: error: Unsupported host architecture. Sorry

* gnu/packages/valgrind.scm (valgrind)[supported-systems]: Remove armhf-linux.
</span></span></td><td>Christopher Baines</td></tr>
<tr><td><span title='2023-04-26 14:34:23 +0200'>2023-04-26</span></td><td><a href='/guix/commit/gnu/packages/valgrind.scm?id=c3509c2148ee74b66a7e4338c626cd3b582ab51c'>gnu: valgrind: Update to 3.20.0.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/valgrind.scm (valgrind): Update to 3.20.0. Remove patch.
[arguments]&lt;phases&gt;: Remove trailing #t.
* gnu/packages/patches/valgrind-enable-arm.patch: Delete file.
* gnu/packages/valgrind.scm (dist_patch_DATA): Unregister patch.

Signed-off-by: Andreas Enge &lt;andreas@enge.fr&gt;
</span></span></td><td>zimoun</td></tr>
<tr><td><span title='2023-04-14 23:37:06 -0400'>2023-04-14</span></td><td><a href='/guix/commit/gnu/packages/valgrind.scm?id=fa2c1689c8972a1cdd111bcbc114c25fbf447904'>gnu: valgrind/interactive: Rely on non-stripped glibc symbols.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/valgrind.scm (valgrind/interactive)
[source]: Remove patches.
[arguments]: Delete field.
* gnu/packages/patches/valgrind-fix-default-debuginfo-path.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): De-register it.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2023-02-09 01:07:22 +0100'>2023-02-09</span></td><td><a href='/guix/commit/gnu/packages/valgrind.scm?id=7ad98c571e1bd19b36b1cde7a49868b589fdb3ca'>gnu: Remove valgrind-3.20.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/valgrind.scm (valgrind-3.20): Delete variable.
(valgrind/interactive): Update to 3.20.0.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Simon Tournier</td></tr>