sys/contrib/zstd: Import zstd 1.4.8
Merge commit 'f6ae97673c28bdb9ae795bd235ab6f26f2536a2d' into main
Changes from 1.4.5:
- https://github.com/facebook/zstd/releases/tag/v1.4.8
- https://github.com/facebook/zstd/releases/tag/v1.4.7 (and there was no public v1.4.6)
Conflicts:
sys/contrib/zstd/lib/common/zstd_internal.h (new ZSTD_NO_INTRINSICS)