Auto-sync with upstream branch master
    
    Upstream commit: 2de7fe62534b7a6461c633114f03e9dff394f5f7
    
    - parse_tunables: Fix typo in comment
    - ldconfig: trace origin paths with -v
    - test-container: print errno when execvp fails
    - [AArch64] Improve integer memcpy
    - Add NEWS entry for CVE-2020-10029 (bug 25487)
    - gcc PR 89877: miscompilation due to missing cc clobber in longlong.h macros
    - mips: Fix wrong INTERNAL_SYSCALL_ERROR_P check from bc2eb9321e
    - elf: Fix wrong indentation from commit eb447b7b4b
    - y2038: linux: Provide __futimesat64 implementation
    - y2038: linux: Provide __lutimes64 implementation
    - y2038: linux: Provide __futimes64 implementation
    - y2038: fix: Add missing libc_hidden_def for __futimens64
    - sparc: Move sigreturn stub to assembly
    - ldbl-128ibm: Let long double files have specific compiler flags
    - ldbl-128ibm-compat: Add tests for IBM long double functions
    - powerpc: Fix feraiseexcept and feclearexcept macros
    - arm: Fix softp-fp Implies (BZ #25635)
    - Remove reference of --without-fp on configure
    - linux/sysipc: Include linux/posix_types.h for __kernel_mode_t
    - Improve IFUNC check [BZ #25506]
    - linux: Clear mode_t padding bits (BZ#25623)
    - linux: Remove aarch64 ipc_priv.h
    - Linux: Use __fstatat64 in fchmodat implementation
    - Linux: Use AT_FDCWD in utime, utimes when calling utimensat
    - S390: Remove backchain-based fallback and use generic backtrace.c.
    - manual: Fix wrong declaration of wcschr [BZ #24654]
    - manual: Fix typo in parse_printf_format example [BZ #24638]