toolchain/musl: bump to version 1.1.23

toolchain/musl: bump to version 1.1.23

new features:
- riscv64 port
- configure now allows customizing AR and RANLIB vars
- header-level support for new linux features in 5.1

major internal changes:
- removed extern __syscall; syscall header code is now fully self-contained

performance:
- new math library implementation for log/exp/pow
- aarch64 dynamic tlsdesc function is streamlined

compatibility & conformance:
- O_TTY_INIT is now defined
- sys/types.h no longer pollutes namespace with sys/sysmacros.h in any profile
- powerpc asm is now compatible with clang internal assembler

changes for new POSIX interpretations:
- fgetwc now sets stream error indicator on encoding errors
- fmemopen no longer rejects 0 size

bugs fixed:
- static TLS for shared libraries was allocated wrong on "Variant I" archs
- crash in dladdr reading through uninitialized pointer on non-match
- sigaltstack wrongly errored out on invalid ss_size when doing SS_DISABLE
- getdents function misbehaved with buffer length larger than INT_MAX
- set*id could deadlock after fork from multithreaded process

arch-specfic bugs fixed:
- s390x SO_PEERSEC definition was wrong
- passing of 64-bit syscall arguments was broken on microblaze
- posix_fadvise was broken on mips due to missing 7-arg syscall support
- vrregset_t layout and member naming was wrong on powerpc64

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>