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.
/table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=a44569899a54d18a70b62498bec3774f0be3f66b'>refs</a><a class='active' href='/guix/log/gnu/packages/patches/audiofile-multiply-overflow.patch'>log</a><a href='/guix/tree/gnu/packages/patches/audiofile-multiply-overflow.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>tree</a><a href='/guix/commit/gnu/packages/patches/audiofile-multiply-overflow.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>commit</a><a href='/guix/diff/gnu/packages/patches/audiofile-multiply-overflow.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/patches/audiofile-multiply-overflow.patch'>
<input type='hidden' name='id' value='a44569899a54d18a70b62498bec3774f0be3f66b'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=a44569899a54d18a70b62498bec3774f0be3f66b'>root</a>/<a href='/guix/log/gnu?id=a44569899a54d18a70b62498bec3774f0be3f66b'>gnu</a>/<a href='/guix/log/gnu/packages?id=a44569899a54d18a70b62498bec3774f0be3f66b'>packages</a>/<a href='/guix/log/gnu/packages/patches?id=a44569899a54d18a70b62498bec3774f0be3f66b'>patches</a>/<a href='/guix/log/gnu/packages/patches/audiofile-multiply-overflow.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>audiofile-multiply-overflow.patch</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/patches/audiofile-multiply-overflow.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-11-10 17:49:14 +0100'>2020-11-10</span></td><td><a href='/guix/commit/gnu/packages/patches/audiofile-multiply-overflow.patch?id=8515ea12d283632e7d0103286e679542d896058b'>gnu: audiofile: Shorten patch file names.</a><span class='msg-avail'>...<span class='msg-tooltip'>At least 'audiofile-division-by-zero-BlockCodec-runPull.patch' could end
up not being included in a tarball.

* gnu/packages/patches/audiofile-Check-the-number-of-coefficients.patch:
Rename to...
* gnu/packages/patches/audiofile-check-number-of-coefficients.patch:
... this.
* gnu/packages/patches/audiofile-division-by-zero-BlockCodec-runPull.patch:
Rename to...
* gnu/packages/patches/audiofile-division-by-zero.patch: ....this.
* gnu/packages/patches/audiofile-signature-of-multiplyCheckOverflow.patch:
Rename to...
* gnu/packages/patches/audiofile-function-signature.patch: ... this.
* gnu/packages/patches/audiofile-Fix-multiply-overflow-sfconvert.patch:
Rename to....
* gnu/packages/patches/audiofile-multiply-overflow.patch: ... this.
* gnu/packages/patches/audiofile-Fix-overflow-in-MSADPCM-decodeSam.patch:
Rename to...
* gnu/packages/patches/audiofile-overflow-in-MSADPCM.patch: ... this.
* gnu/packages/audio.scm (audiofile)[source]: Adjust accordingly.
* gnu/local.mk (dist_patch_DATA): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>