changes in sbcl-2.6.2 relative to sbcl-2.6.1:
  * minor incompatible change: IMAGPART of a negative float returns 0.0, not
    -0.0, consistent with a treatment of reals as complexes with an imaginary
    part of strictly 0.0, but strictly incompatible with the requirement that
    the IMAGPART equal (* 0 <float>)
  * platform support:
    ** support for Windows on arm64 has been added.  (thanks to Masatoshi SANO)
    ** various mismatches and bugs related to mismatches between Win32 and
       Unix have been addressed.
    ** fixed an issue in unsigned 32-bit compare-and-swap on RISC-V (thanks to
       Andreas Schwab) and LoongArch.
    ** fixed the integration of the system with the (lack of) floating point
       traps on RISC-V.  (thanks to Andreas Schwab)
    ** implemented the missing runtime breakpoint-related functions on RISC-V.
       (lp#2130944)
    ** fix for assembling large relative jumps on MIPS.
    ** fix for GC safety of function calling on RISC-V and LoongArch.
       (reported by Will Sinatra)
    ** support little-endian PPC64 to write cores in ELF format.
    ** fix for SB-POSIX:STAT on Windows with the UCRT C library.
    ** numerous other fixes related to architecture definitions, particularly
       on RISC-V, but also on LoongArch, MIPS, PPC and PPC64, and ARM64.
  * enhancement: support stack allocation of results for struct return values
    from alien functions.  (thanks to Jesse Bouwman)
  * bug fix: rounding of floats converted from ratios.  (lp#2139007)
  * bug fix: SCALE-FLOAT and RATIONALIZE on denormals gave wrong answers, and
    converting ratios to denormals is both more correct and faster.
  * bug fix: the ~E FORMAT directive scales its float more correctly.
    (lp#1854151, lp#2016431, lp#2125287, reported by Michał "phoe" Herda,
    Robert Dodier and Francis Wright)
  * bug fix: the error when failing to bind in DESTRUCTURING-BIND is now a
    PROGRAM-ERROR.
  * bug fix: the compiler respects INLINE and NOTINLINE declarations to
    control compiler macros that apply to macros.  (lp#1490345)
  * bug fix: converting bignums to float will trap or return floating point
    infinities as appropriate to the prevailing floating point modes.
  * bug fix: division with a (COMPLEX FLOAT) result will be more consistent
    with results involving negative zeros.
  * bug fix: allow the full range of hash values in weak hash-tables with
    user-defined hash functions.  (lp#2141482, reported by Patrick Poitras)
  * bug fix: malformed OPTIMIZE declarations no longer cause the compiler to
    stop.
  * bug fix: symbols with terminating macro characters in their names (or
    non-terminating ones at the start) print with escapes when *PRINT-ESCAPE*
    is true.
  * bug fix: documentation issues, in README and the manual.  (thanks to Carl
    Gay)
  * bug fix: compiler crash while transforming arithmetic operations on known
    non-numeric inputs.  (lp#2142297)
  * bug fix: unsafe concurrent access to synchronized weak hash tables.
    (lp#2142714)
  * optimization: avoid consing when right-shifting a bignum gives a fixnum
    result.
  * optimization: various type tests in the presence of intersecting
    constraints do less redundant work.