Сабж. Изменения:
     * minor incompatible change: SB-EXT:*INTEXP-MAXIMUM-EXPONENT* is removed.
     * enhancement: TRACE ... :REPORT {TRACE,NIL} now work as advertised in the documentation string (based on
       patch by Patrick Stein)
     * enhancement: support unboxed signed-word structure slots on x86, x86-64 and ARM64. (#377616)
     * optimization: faster logical bit-array operations on multidimensional arrays.
     * optimization: better GC performance in the presence of many threads. (patch by Ilya Perminov, #1339924)
     * optimization: multiple-value-call is optimized with multiple argument forms, not just one. (#753803)
     * bug fix: MAKE-ALIEN-STRING returns the number of allocated bytes as a second value as advertised (reported
       by Johann 'Myrkraverk' Oskarsson)
     * bug fix: when TO-READTABLE is supplied to COPY-READTABLE, it will contain only the macros in FROM-READTABLE
       and no others. (#1631506)
     * enhancement: gencgc has been modified for x86-64 on Linux and macOS to a support mark-and-sweep as well as
       the traditional copying strategy. It is conceivable that some applications might be adversely affected.
       Please see ':immobile-space' in 'base-target-features.lisp-expr' for further details, and possible reasons
       to disable this feature.
     * enhancement: x86-64 supports shrinking the fixed overhead in a structure from 2 words to 1 word, reducing
       memory consumption in applications which create many small structures.





