MFV: zstd 1.5.2

Merge commit 'b3392d84da5bf2162baf937c77e0557f3fd8a52b' into zstd_1.5.2

full changelog: https://github.com/facebook/zstd/compare/v1.4.8...v1.5.2

Updated sys/kern/subr_compressor.c to new API

MFC after: 3 days
Relnotes: yes
Sponsored by: Klara, Inc.

Update to Zstandard 1.4.5

As usual, the full release notes are found on Github:

https://github.com/facebook/zstd/releases/tag/v1.4.5

Notable changes include:

* Improved decompress performance on amd64 and arm (5-10%
and 15-50%, respectively).
* '--patch-from' zstd(1) CLI option, which provides something like a very fast
version of bspatch(1) with slightly worse compression. See release notes.

In this update, I dropped the 3-year old -O0 workaround for an LLVM ARM bug;
the bug was fixed in LLVM SVN in 2017, but we didn't remove this workaround
from our tree until now.

MFC after: I won't, but feel free
Relnotes: yes

Update to Zstandard 1.4.2

The full release notes for 1.4.1 (skipped) and 1.4.2 can be found on Github:

https://github.com/facebook/zstd/releases/tag/v1.4.1
https://github.com/facebook/zstd/releases/tag/v1.4.2

These are mostly minor updates; 1.4.1 purportedly brings something like 7%
faster decompression speed.

Relnotes: yes

Update to Zstandard 1.4.0

The full release notes can be found on Github:

https://github.com/facebook/zstd/releases/tag/v1.4.0

Relnotes: yes

Update to Zstandard 1.3.8

This merge brings in a couple new files, which needed to be attached to the
build; a new dependency on <limits.h>, which must be stubbed; and a name
change in the Context parameter constants, from ZSTD_p_foo to ZSTD_c_foo.

Significantly, it fixes a kernel build error with GCC where floating-point
functions were included in the kernel build, by hiding them under the same
compile-time #ifdef that already covered their invocation. That issue was
introduced to FreeBSD in the 1.3.7 update and tracked upstream here:

https://github.com/facebook/zstd/issues/1386

The full 1.3.8 release notes can be found on Github:

https://github.com/facebook/zstd/releases/tag/v1.3.8

Relnotes: yes