toolchain/musl: update to version 1.1.22

toolchain/musl: update to version 1.1.22

new features:
- priority-inheritance mutexes
- membarrier syscall, pre-registration to use it, fallback emulation
- header-level support for new linux features in 4.19, 4.20, 5.0

major internal changes:
- complete, async-safe view of all existent threads as global list
- robust __synccall based on new thread list
- new dynamic TLS is installed synchronously at dlopen
- TLSDESC resolver functions no longer make bad ABI assumptions to call C
- resolved shared library dependencies are now recorded

compatibility & conformance:
- dependency-order shared library constructor execution
- sigaltstack no longer rejects SS_AUTODISARM, future flags
- FILE is now a complete (dummy) type in pre-C11 feature profiles
- setvbuf reports failure on invalid arguments
- TSVTX is exposed unconditionally in tar.h
- multithreaded set*id() no longer depends on /proc
- key slot reuse after pthread_key_delete no longer depends on /proc

bugs fixed:
- failures in multithreaded set*id() with concurrent thread creation/exit
- interposed free was called from invalid/inconsistent contexts
- freeaddrinfo performed invalid free of some partial results lists
- dlsym dependency order search had false negatives and false positives
- dn_skipname gave wrong results for labels with 8-bit content
- dcngettext clobbered errno, often breaking printing of error messages
- sscanf read past end of buffer under certain conditions (1.1.21 regression)
- pthread_key_create spuriously failed under race condition (1.1.21 regression)
- fdopendir wrongly succeeded with O_PATH file descriptors
- gets behaved incorrectly in presence of null bytes
- namespace violations in c11 tsd and mutex function dependencies
- incorrect prototype for makecontext (unimplemented)

arch-specfic bugs fixed:
- s390x had wrong values for POSIX_FADV_DONTNEED/_NOREUSE

Extensively tested on dozens of devices, covering most popular architectures.

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Signed-off-by: Dainis Jonitis <dainis.jonitis@ubnt.com>
Signed-off-by: Roman Yeryomin <roman@advem.lv>