package/glibc: fix x86_64 builds with -Os

Backport upstream commit for x86_64 builds with -Os reported by [1].

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=29576

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/3134229902
https://gitlab.com/buildroot.org/buildroot/-/jobs/3134229956
http://autobuild.buildroot.net/results/5b442f95587ddc65a995bbd9e310c88a66c55b1f

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Reviewed-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/glibc/0002-x86-Fix-Os-build-BZ-29576.patch

@@ -0,0 +1,48 @@
+From 3935b543adcb9a46ab79f8931bc489068b049378 Mon Sep 17 00:00:00 2001
+From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
+Date: Wed, 21 Sep 2022 10:51:08 -0300
+Subject: [PATCH] x86: Fix -Os build (BZ #29576)
+
+The compiler might transform __stpcpy calls (which are routed to
+__builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy
+multiarch implementation does not build any working symbol due
+ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld).
+
+Checked on x86_64-linux-gnu.
+Reviewed-by: Carlos O'Donell <carlos@redhat.com>
+Tested-by: Carlos O'Donell <carlos@redhat.com>
+
+(cherry picked from commit 9dc4e29f630c6ef8299120b275e503321dc0c8c7)
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ sysdeps/x86_64/multiarch/rtld-strcpy.S | 18 ++++++++++++++++++
+ 1 file changed, 18 insertions(+)
+ create mode 100644 sysdeps/x86_64/multiarch/rtld-strcpy.S
+
+diff --git a/sysdeps/x86_64/multiarch/rtld-strcpy.S b/sysdeps/x86_64/multiarch/rtld-strcpy.S
+new file mode 100644
+index 0000000000..19439c553d
+--- /dev/null
++++ b/sysdeps/x86_64/multiarch/rtld-strcpy.S
+@@ -0,0 +1,18 @@
++/* Copyright (C) 2022 Free Software Foundation, Inc.
++   This file is part of the GNU C Library.
++
++   The GNU C Library is free software; you can redistribute it and/or
++   modify it under the terms of the GNU Lesser General Public
++   License as published by the Free Software Foundation; either
++   version 2.1 of the License, or (at your option) any later version.
++
++   The GNU C Library is distributed in the hope that it will be useful,
++   but WITHOUT ANY WARRANTY; without even the implied warranty of
++   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
++   Lesser General Public License for more details.
++
++   You should have received a copy of the GNU Lesser General Public
++   License along with the GNU C Library; if not, see
++   <https://www.gnu.org/licenses/>.  */
++
++#include "../strcpy.S"
+-- 
+2.34.3
+