glibc: Bring in CVE fixes and other bugfixes from 2.31 release branch

Drop 0016-Add-unused-attribute.patch since its fixed by Rewrite iconv
option parsing [BZ #19519] [1]

Upgrade to latest on 2.31 branch which brings following bug fixes

* 6fdf971c9db (origin/release/2.31/master) Add NEWS entry for CVE-2016-10228 (bug 19519)
* 70d585151c0 Rewrite iconv option parsing [BZ #19519]
* 1c8efe848bf powerpc: Fix incorrect cache line size load in memset (bug 26332)
* 7611339a9b5 nptl: Zero-extend arguments to SETXID syscalls [BZ #26248]
* 21b760cc2fa Disable warnings due to deprecated libselinux symbols used by nss and nscd
* 6f3459f9859 Add NEWS entry for CVE-2020-6096 (bug 25620)
* 64246fccafc arm: CVE-2020-6096: Fix multiarch memcpy for negative length [BZ #25620]
* 9bbd2b61729 arm: CVE-2020-6096: fix memcpy and memmove for negative length [BZ #25620]
* 4e8a33a9590 NEWS: Mention BZ 25933 fix
* fd15ba932d2 Fix avx2 strncmp offset compare condition check [BZ #25933]
* 3a44844c97a nss_compat: internal_end*ent may clobber errno, hiding ERANGE [BZ #25976]
* c8391752678 aarch64: fix strcpy and strnlen for big-endian [BZ #25824]
* 10947412240 aarch64: Accept PLT calls to __getauxval within libc.so
* a98b8b221cf NEWS: Mention fixes for BZ 25810/25896/25902/25966
* 4c833bbebe3 x86-64: Use RDX_LP on __x86_shared_non_temporal_threshold [BZ #25966]
* 3b9ceb33204 NEWS: Mention bug 25639 fixed in 2.31 branch
* bb44fe7711a oc_FR locale: Fix spelling of April (bug 25639)
* f2ac7920474 oc_FR locale: Fix spelling of Thursday (bug 25639)
* 18fdba553dd Add a C wrapper for prctl [BZ #25896]
* 7c9e054afdd powerpc: Rename argN to _argN in LOADARGS_N [BZ #25902]
* 9c5ae39a644 Add C wrappers for process_vm_readv/process_vm_writev [BZ #25810]
* 63c3696a4ac Mark unsigned long arguments with U in more syscalls [BZ #25810]
* 5b9d49293b7 Add a syscall test for [BZ #25810]
* 496b5963a75 Add SYSCALL_ULONG_ARG_[12] to pass long to syscall [BZ #25810]
* 04330f85263 x32: Properly pass long to syscall [BZ #25810]
* de371d1581f Fix build with GCC 10 when long double = double.
* ece4e11d55d Add new file missed in previous hppa commit.
* 91b909315c4 Fix data race in setting function descriptors during lazy binding on hppa.
* b999c0098ae nios2: delete sysdeps/unix/sysv/linux/nios2/kernel-features.h
* 54ba2541b3a mips: Fix bracktrace result for signal frames
* 83d3eec6728 stdlib: Move tst-system to tests-container
* ad9b0037ccc support/shell-container.c: Add builtin kill
* 2448ba1d724 support/shell-container.c: Add builtin exit
* 5810e6d75ff support/shell-container.c: Return 127 if execve fails
* d39fb022c26 Add NEWS entry for CVE-2020-1751 (bug 25423)
* 46bbbd46223 posix: Fix system error return value [BZ #25715]
* 3937f6806d9 Add NEWS entry for CVE-2020-1752 (bug 25414)
* ab029a2801d Fix use-after-free in glob when expanding ~user (bug 25414)
* a3189fb15b4 Update syscall lists for Linux 5.5.
* 05c08d5aea9 NEWS: update list of bugs fixed on the 2.31 branch
* 123d48b33a5 Add NEWS entry for CVE-2020-10029 (bug 25487)
* 03f44ce0938 math/test-sinl-pseudo: Use stack protector only if available
* e85a88e00c1 sparc: Move sigreturn stub to assembly
* a9ae2062d57 arm: Fix softp-fp Implies (BZ #25635)
* da6ce60e3cb linux/sysipc: Include linux/posix_types.h for __kernel_mode_t
* 9db2970506c linux: Clear mode_t padding bits (BZ#25623)
* 44f2c26ee4f i386: Use comdat instead of .gnu.linkonce for i386 setup pic register (BZ #20543)
* f2d95cf030f Improve IFUNC check [BZ #25506]
* 9f997ceca28 Avoid ldbl-96 stack corruption from range reduction of pseudo-zero (bug 25487).

[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=70d585151c03ede999bd2ad5a724243914cb5f54



Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>