changes in sbcl-1.2.8 relative to sbcl-1.2.7:
* enhancement: better error and warning messages. (lp#1314767, lp#736383)
* enhancement: backtrace for invalid argument count produces the exact
supplied arguments including the extra ones, on x86, x86-64 and ARM.
* enhancement: a STYLE-WARNING is signaled for DEFSTRUCT accessors which
are used before the structure is defined; similarly for the predicate.
* optimization: FORMAT NIL with only ~a and string arguments is transformed
into CONCATENATE.
* optimization: POSITION and FIND when inlined into code that is compiled
with qualities of safety < 2 and speed > space will no longer signal
an error on circular lists, but will potentially loop forever if given
no :END constraint. As was always the case, calls that are not inlined
are safe regardless of lexical policy.
* bug fix: CLOS methods compiled with (OPTIMIZE (DEBUG 0))
no longer cause debugger failure when printing a backtrace
* bug fix: more resilience to deleted code. (lp#1308328, lp#1390544)
* bug fix: the CLHS example of MAKE-LOAD-FORM involving TREE-WITH-PARENT
did not work, and now it does.