Auto-sync with upstream master
    
    Upstream commit: 403143e1df85dadd374f304bd891be0cd7573e3b
    
    - x86-64: Align L(SP_RANGE)/L(SP_INF_0) to 8 bytes (swbz#21955)
    - powerpc: Add values from Linux 4.8 to <elf.h>
    - S390: Add new s390 platform z14.
    - Various locale fixes (swbz#14925, swbz#20008, swbz#20482, swbz#12349
      swbz#19982, swbz#20756, swbz#20756, swbz#21836, swbz#17563, swbz#16905,
      swbz#21920, swbz#21854)
    - NSS: Replace exported NSS lookup functions with stubs (swbz#21962)
    - i386: Do not set internal_function
    - assert: Suppress pedantic warning caused by statement expression (swbz#21242)
    - powerpc: Restrict xssqrtqp operands to Vector Registers (swbz#21941)
    - sys/ptrace.h: remove obsolete PTRACE_SEIZE_DEVEL constant (swbz#21928)
    - Remove __qaddr_t, __long_double_t
    - Fix uc_* namespace (swbz#21457)
    - nss: Call __resolv_context_put before early return in get*_r (swbz#21932)
    - aarch64: Optimized memcpy for Qualcomm Falkor processor
    - manual: Document getcontext uc_stack value on Linux (swbz#759)
    - i386: Add <startup.h> (swbz#21913)
    - Don't use IFUNC resolver for longjmp or system in libpthread (swbz#21041)
    - Fix XPG4.2 bits/sigaction.h namespace (swbz#21899)
    - x86-64: Add FMA multiarch functions to libm
    - i386: Support static PIE in start.S
    - Compile tst-prelink.c without PIE (swbz#21815)
    - x86-64: Use _dl_runtime_resolve_opt only with AVX512F (swbz#21871)
    - x86: Remove __memset_zero_constant_len_parameter (swbz#21790)