+changes in sbcl-0.8.21 (0.9alpha.1?) relative to sbcl-0.8.20:
+ * incompatible change: the top level REPL now has only an ABORT
+ restart associated with it, not TOPLEVEL and ABORT as it used to.
+ TOP and TOPLEVEL are now available as debugger commands for
+ returning to the top level.
+ * incompatible change: forms evaluated in the REPL now use the
+ global optimization policy.
+ * incompatible change: user- and system-initialization files are
+ no longer processed with LOAD, but by READ and EVAL; hence the
+ global optimization policy, startup package, readtable, etc,
+ can be set by them.
+ * internal entry point details and argument counts no longer appear
+ in backtraces unless explicitly requested by setting
+ SB-DEBUG:*SHOW-ENTRY-POINT-DETAILS*.
+ * built-in and standard functions no longer have names like "top
+ level local call to FOO".
+ * fixed bug 32: functions defined in non-null lexical environments
+ now have more legible printed representation
+ * fixed bug 33: functions defined in non-null lexical environemnts
+ are now more amenable to inspection by INSPECT.
+ * workaround for bug 354: XEPs no longer appear in backtraces unless
+ explicitly requested.
+ * fixed bug: receiving the signal which results from attempting to
+ write to mprotect()ed memory (SIGSEGV on Linux and some *BSDs,
+ SIGBUS on other *BSDs) on architectures where the C stack is also
+ the Lisp stack (x86 and x86-64) from foreign code no longer leads
+ to debugger confusion or wild instability. (reported by Cheuksan
+ Wang)
+ * fixed bug: COUNT and EQUAL no longer issue compiler efficiency
+ notes when operating on objects known to be SIMPLE-BIT-VECTORs.
+ (reported by Lutz Euler)
+ * fixed bug: (TYPEP X '(MEMBER ...)) no longer returns a list in
+ compiled code. (reported by Paul Dietz)
+ * fixed bug 276b: mutating with MULTIPLE-VALUE-SETQ a binding of a
+ specialized parameter to a method to something that is not TYPEP
+ the specializer is now possible.
+ * fixed bug: the MAKE-INSTANCE optimization is now correct in the
+ face of package deletion.
+ * fixed bug: LOAD should bind *LOAD-PATHNAME* to the merged
+ pathname. (reported by David Tolpin on c.l.l)
+ * contrib improvement: the SB-SIMPLE-STREAMS contrib now defines
+ STRING-SIMPLE-STREAM and FILE-SIMPLE-STREAM as subclasses of
+ STRING-STREAM and FILE-STREAM, respectively.
+ * contrib improvement: SB-INTROSPECT handles more of SLIME's needs
+ than previously; in addition, its test suite is now run on build.
+ (thanks to Luke Gorrie)
+ * a more robust x86-64 disassembler. (thanks to Lutz Euler)
+ * optimization: added a immediate representation for single-floats
+ on x86-64
+ * fixed some bugs revealed by Paul Dietz' test suite:
+ ** MISC.564: defined out-of-line version of %ATAN2 on x86.
+
changes in sbcl-0.8.20 (0.9alpha.0?) relative to sbcl-0.8.19:
* fixed inspection of specialized arrays. (thanks to Simon Alexander)
* fixed disassembly of SHLD and SHRD on x86. (thanks to David