overlay coreos/user-patches: Add a patch for app-arch/sharutils

sdk_container/src/third_party/coreos-overlay/coreos/user-patches/app-arch/sharutils/0000-gettext.patch

@@ -0,0 +1,11 @@
+diff -u3 -r sharutils-4.15.2/src/local.h sharutils-4.15.2-patched/src/local.h
+--- sharutils-4.15.2/src/local.h	2015-05-30 17:35:32.000000000 +0200
++++ sharutils-4.15.2-patched/src/local.h	2024-11-28 20:18:51.360160618 +0100
+@@ -37,6 +37,7 @@
+ #include "base64.h"
+ #include "dirname.h"
+ #include "error.h"
++#include "gettext.h"
+ #include "idcache.h"
+ #include "inttostr.h"
+ #include "locale.h"

sdk_container/src/third_party/coreos-overlay/coreos/user-patches/app-arch/sharutils/README.md

@@ -0,0 +1,13 @@
+`0000-gettext.patch` is for fixing a build with USE=-nls:
+
+```
+uuencode.c: In function 'process_opts':
+uuencode.c:204:3: error: implicit declaration of function 'bindtextdomain' [-Wimplicit-function-declaration]
+  204 |   bindtextdomain (PACKAGE, LOCALEDIR);
+      |   ^~~~~~~~~~~~~~
+uuencode.c:205:3: error: implicit declaration of function 'textdomain' [-Wimplicit-function-declaration]
+  205 |   textdomain (PACKAGE);
+      |   ^~~~~~~~~~
+```
+
+Should probably be upstreamed to sharutils and to Gentoo if it works.