sbcl-2.2.6 released

Dear all,

This morning I have released SBCL 2.2.6, and uploaded materials to
SourceForge.  The changes in this version are summarized below.

It's perhaps worth mentioning a few things related to these notes in
more detail.  Firstly, the new core compression format uses zstd; to
build the system with support for core compression (not enabled by
default), as well as providing the --with-sb-core-compression build
option, the build host will need development artifacts for libzstd -- on
my Debian system, that's provided in the libzstd-dev package.

Secondly, we have integrated the new sb-simd contrib developed by Marco
Heisig and others.  It is only built on systems which fully support
AVX2, and even then can be turned off using the --without-sb-simd build
option (which may be desireable as it adds significantly to the build
time of the system).  Please report successes and particularly failures
with sb-simd to the sbcl-devel mailing list.

Additionally, we have done some behind-the-scenes administration with
the DNS, the major result of which is that we now support SSL on
<https://sbcl.org/> and <https://www.sbcl.org/>.  There should be no
other observable change with the web presence; again, if you do notice
anything awry, please report it to sbcl-devel.

Best wishes,

Christophe

changes in sbcl-2.2.6 relative to sbcl-2.2.5:
  * minor incompatible change: support for 32-bit x86 on macOS has been
    removed.
  * new contrib: sb-simd, to provide a convenient interface for SIMD
    programming on x86-64.  (Thanks to Marco Heisig and other sb-simd
    contributors)
  * enhancement: core compression now uses zstd instead of zlib.  (lp#1881089)
  * enhancement: provide compiler warnings for specialized array type
    mismatches in CONCATENATE.
  * enhancement: provide compiler warnings for bad sequence bounding index
    designator arguments to sequence functions.
  * enhancement: The sb-mpfr contrib now allows coercion from MPFR-FLOATs
    to CL:RATIONAL.  (Thanks to Robert Smith)
  * bug fix: fix compilation failure related to declaiming types of constants.
    (lp#1977726, reported by Pierre Neidhardt)
  * bug fix: fix race condition in CLOS optimized constructors.  (lp#1951341)
  * bug fix: fix too-eager elision of allocation barriers when initializing
    closure and structure objects.
  * optimization: fasl files are now usually smaller (up to 10% on default
    policy) and may load faster, especially on high debug.
  * optimization: faster string comparisons on arm64, x86-64.
  * optimization: faster [n]string-down/upcase on arm64, x86-64.
  * optimization: faster [n]reverse for 8- and 32-bit element vectors on
    arm64, x86-64.
  * optimization: faster type tests for (CONS (EQL symbol)) on x86-64.