Auto-sync with upstream branch release/2.27/master
    
    Upstream commit: 55ad82e45c313454de657931898e974a7a036cad
    
    - i386: Fix memmove issue (swbz#22644)
    - RISC-V: fmax/fmin: Handle signalling NaNs correctly (swbz#22884)
    - RISC-V: Do not initialize $gp in TLS macros
    - cs_CZ locale: Add alternative month names (swbz#22963)
    - Greek (el_CY, el_GR) locales: Introduce ab_alt_mon (swbz#22937)
    - lt_LT locale: Update abbreviated month names (swbz#22932)
    - ca_ES locale: Update LC_TIME (swbz#22848)
    - i386: Fix i386 sigaction sa_restorer initialization (swbz#21269)
    - Fix multiple definitions of __nss_*_database (swbz#22918)
    - Fix netgroup cache keys (swbz#22342)
    - linux/powerpc: sync sys/ptrace.h with Linux 4.15 (swbz#22433, swbz#22807)
    - powerpc: Undefine Linux ptrace macros that conflict with __ptrace_request
    - Add missing “reorder-end” in LC_COLLATE of et_EE (swbz#22517)
    - linux/aarch64: sync sys/ptrace.h with Linux 4.15 (swbz#22433)
    - [RISC-V] Fix parsing flags in ELF64 files (swbz#22827)