Log Message:
Update to SBCL 1.3.21

New in version 1.3.21

 - minor incompatible change: the CLOBBER-IT restart for defstruct
   redefintion has been removed after a 15 year deprecation cycle.
   Use the new name, RECKLESSLY-CONTINUE. Note also that this restart
   is hidden if deemed unsafe due to altered placement of untagged slots
   in the structure.
 - enhancement: the assignment of -DSBCL_PREFIX= in src/runtime/GNUmakefile
   can be removed as a local patch, which results in an sbcl executable
   that finds its core file relative to itself by looking in "../lib/sbcl".
 - enhancement: backends using the generational GC are able to relocate
   dynamic space anywhere the operating system places it. This feature
   can be disabled by removing :relocatable-heap from the build configuration.
   Not supported on Windows.
 - enhancement: DEFMETHOD no longer signals IMPLICIT-GENERIC-FUNCTION-WARNING.
 - enhancement: better type conflict detection for high order functions,
   e.g. (find x "123" :test #'=)
 - enhancement: the tabular output of ROOM is aligned dynamically,
   preventing misaligned tables for larger sizes or counts.
 - enhancement: ROOM reports on immobile space if applicable.
 - optimization: optimized external-format routines.
 - bug fix: SB-INTROSPECT:ALLOCATION-INFORMATION returns :IMMOBILE
   instead of :FOREIGN for objects in immobile space.
 - bug fix: dotted lists in special forms and function call forms signal
   an appropriate error
 - bug fix: EQUALP hash tables with pathname keys now ignore internal slots.
   (#1712944, reported by Jason Miller)

New in version 1.3.20

 - 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. (#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.

New in version 1.3.19

 - enhancement: specialized arrays can be printed readably without using
   *read-eval*
 - enhancement: SB-DEBUG:PRINT-BACKTRACE truncates huge string arguments.
   The full string remains available for inspection via (SB-DEBUG:ARG).
 - bug fix: backtracing from several threads at once could fail
 - bug fix: floating-point infinities could not be used as keys in EQUALP
   hash tables. (#1696274)
 - bug fix: random sb-fasteval failures. (#1642708)
 - bug fix: align the stack in callback wrappers to defend against C compiler
   over-aggressive use of SIMD. (#1697528)
 - bug fix: don't try to find the class when reporting that a class does not
   exist for a primitive type. (#1697226)