changes in sbcl-1.3.20 relative to sbcl-1.3.19:
* minor incompatible change: DEF{GENERIC,METHOD} no longer accept some
illegal lambda lists such as (defgeneric bar (foo &key foo)) or
(defgeneric baz (t)) that were accepted before.
* optimization: a valueless &AUX binding in a BOA constructor does not
force all slots reads in safe code to perform a full type check.
* optimization: ATOMIC-PUSH and ATOMIC-POP generate better code
* bug fix: the low-level debugger would erroneously print - or not print
as the case may be - "(bad-address)" for some objects depending whether
the --dynamic-space-size argument was used at Lisp startup
* bug fix: a DEFCONSTANT with a non non-eql-comparable object as the value
could cause miscompilation if that constant appeared as the default
expression for an &OPTIONAL binding
* bug fix: generic function lambda lists are now checked for repeated
and otherwise illegal entries. (lp#1704114)
* bug fix: setting gencgc_verbose = 1 could cause deadlock in fprintf()
depending on the platform's stdio implementation. The relevant code
has been changed to use snprintf() and write() instead.