+changes in sbcl-0.8.22 relative to sbcl-0.8.21:
+ * incompatible change: the --noprogrammer option, deprecated since
+ version 0.7.5, has been removed. Please use the equivalent
+ --disable-debugger option instead.
+ * incompatible change: finalizers and *AFTER-GC-HOOKS* are now run with
+ interrupts enabled.
+ * incompatible change: support for *BEFORE-GC-HOOKS* (that have been
+ inoperational for a while now) has been completely removed.
+ * null lexical environments are now printed as #<NULL-LEXENV>,
+ significantly reducing the amount of clutter in typical backtraces.
+ * documentation on weak pointers, finalization, and after GC hooks
+ has been added to the manual.
+ * optimization: REPLACE on declared (UNSIGNED-BYTE 8) vectors, as well
+ as other specialized array types, is much faster. SUBSEQ and
+ COPY-SEQ on such arrays have also been sped up.
+ * fixed bug: finalizers are now thread-safe. (thanks to Gabor Mellis)
+ * fixed bug: finalizers and after GC hooks that cause consing are now
+ safe.
+ * fixed bug: compiler error messages and summaries are now printed to
+ *ERROR-OUTPUT*, not *STANDARD-OUTPUT*.
+ * fixed inference of the upper bound of an iteration variable.
+ (reported by Rajat Datta).
+ * fixed bug 373: caused by erronous compilation of references to alien
+ variables in the runtime on ppc/darwin.
+ * fixed bug 376: CONJUGATE type deriver.
+ * fixed infinite looping of ALIEN-FUNCALL, compiled with high DEBUG.
+ (reported by Baughn on #lisp)
+ * a cross-compiler bug on non-x86 platforms has been identified and
+ fixed. (thanks to Bruno Haible)
+ * improvements to the MIPS runtime code for increased stability.
+ (thanks to Thiemo Seufer)
+ * increased the maximimum compact environment size to allow
+ purify on images with large amounts of functions. (thanks to Cyrus Harmon)
+ * partial workaround for bug 135: don't name the function we're
+ calling for hairy cases of EVAL, so as not to accumulate one environment
+ entry per call to EVAL. (reported by Kevin Reid)
+ * improvements to the x86-64 disassembler. (thanks to Lutz Euler)
+ * optimization: type testing for non-vector arrays should be faster.
+ * fixed TRACE :ENCAPSULATE NIL, added support for :ENCAPSULATE NIL
+ on x86-64
+ * bug fix: setting 31st element of a bit vector to zero did not work
+ on Alpha-32.
+ * fixed some bugs related to Unicode integration:
+ ** the restarts for recovering from input and output encoding
+ errors only appear when there is in fact such an error to
+ handle.
+ * fixed some bugs revealed by Paul Dietz' test suite:
+ ** MISC.549 and similar: late transformation of unsafe type
+ assertions into derived types caused unexpected code
+ transformations.
+ ** SCALE-FLOAT type deriver is less wrong.
+ ** type derivers for EXP, LOG and similar functions compute result
+ types for complex arguments better.
+ ** (MISC.563) CONJUGATE type deriver works for very restricted
+ complex types.
+ ** out-of-line type testers for character strings are available.
+ ** EQUAL compiler transform understands specialness of objects
+ of type BIT-VECTOR.
+ ** accessing double-floats stored on the stack now works on x86-64.
+ ** debugger internals could sometimes create invalid lispobjs,
+ resulting in GC crashes.
+ ** MISC.548: type check weakening can convert required type into
+ optional.
+
changes in sbcl-0.8.21 (0.9alpha.1?) relative to sbcl-0.8.20:
* incompatible change: thread support for non-NPTL systems has
been removed - locking is buggy and unreliable. A threaded