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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nux-libre/4.19-arm64.conf?id=708742109c925dbd41823639f7e589812794b9e9&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-01-15 14:31:21 +0100'>2020-01-15</span></td><td><a href='/guix/commit/gnu/packages/aux-files/linux-libre/4.19-arm64.conf?id=2c97c980a0ca5f77464cd74207e29d835376f85b'>gnu: linux-libre: Include more framebuffer font sizes.</a><span class='msg-avail'>...<span class='msg-tooltip'>Add the 32x16 Terminus font for ‘high-DPI’ screens, and a 6x10 font that
allows for more (debugging) information to be displayed on standard-DPI
ones, while still being pleasant to read.

* gnu/packages/aux-files/linux-libre/4.14-arm.conf,
gnu/packages/aux-files/linux-libre/4.14-i686.conf,
gnu/packages/aux-files/linux-libre/4.14-x86_64.conf,
gnu/packages/aux-files/linux-libre/4.19-arm.conf,
gnu/packages/aux-files/linux-libre/4.19-arm64.conf,
gnu/packages/aux-files/linux-libre/4.19-i686.conf,
gnu/packages/aux-files/linux-libre/4.19-x86_64.conf,
gnu/packages/aux-files/linux-libre/4.4-i686.conf,
gnu/packages/aux-files/linux-libre/4.4-x86_64.conf,
gnu/packages/aux-files/linux-libre/4.9-i686.conf,
gnu/packages/aux-files/linux-libre/4.9-x86_64.conf,
gnu/packages/aux-files/linux-libre/5.4-arm-veyron.conf,
gnu/packages/aux-files/linux-libre/5.4-arm.conf,
gnu/packages/aux-files/linux-libre/5.4-arm64.conf,
gnu/packages/aux-files/linux-libre/5.4-i686.conf,
gnu/packages/aux-files/linux-libre/5.4-x86_64.conf:
Set CONFIG_FONTS=y, CONFIG_FONT_TER16x32=y, and CONFIG_FONT_6x10=y.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-09-18 19:04:59 +0800'>2019-09-18</span></td><td><a href='/guix/commit/gnu/packages/aux-files/linux-libre/4.19-arm64.conf?id=62790449e61bfdf7835790fae89e49c210a08418'>gnu: linux-libre: Enable all nftables families.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/aux-files/linux-libre/4.19-arm.conf,
gnu/packages/aux-files/linux-libre/4.19-arm64.conf,
gnu/packages/aux-files/linux-libre/4.19-i686.conf,
gnu/packages/aux-files/linux-libre/4.19-x86_64.conf,
gnu/packages/aux-files/linux-libre/5.2-arm.conf,
gnu/packages/aux-files/linux-libre/5.2-arm64.conf,
gnu/packages/aux-files/linux-libre/5.2-i686.conf,
gnu/packages/aux-files/linux-libre/5.2-x86_64.conf: Set CONFIG_NF_TABLES_INET,
CONFIG_NF_TABLES_NETDEV, CONFIG_NF_TABLES_IPV4, CONFIG_NF_TABLES_IPV6 and
CONFIG_NF_TABLES_BRIDGE to 'y', and related options to 'm'.
</span></span></td><td>宋文武</td></tr>
<tr><td><span title='2019-01-23 21:32:14 -0500'>2019-01-23</span></td><td><a href='/guix/commit/gnu/packages/aux-files/linux-libre/4.19-arm64.conf?id=ff0b73028c0bbbcbf352989ed3863947357c3bce'>gnu: linux-libre: Make CRYPTO_CRC32C a built-in on arm64.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/34162&gt;
Reported by Vagrant Cascadian &lt;vagrant@debian.org&gt;

Note that CRYPTO_CRC32C was already a built-in in our default
configurations for other systems.

* gnu/packages/aux-files/linux-libre/4.20-arm64.conf,
gnu/packages/aux-files/linux-libre/4.19-arm64.conf
(CONFIG_CRYPTO_CRC32C): Change from 'm' to 'y'.
</span></span></td><td>Mark H Weaver</td></tr>