changes in sbcl-1.4.0 relative to sbcl-1.3.21:
* minor incompatible change: DESTRUCTURING-BIND treats non-toplevel () as
nested empty pattern. This seems to be what the standard mandates, so
conforming code should not be affected.
* ehancement: (GC :GEN 7) with gencgc will zero-fill dead pseudo-static
objects so that they do not spuriously cause reachability of objects that
would have been otherwise dead.
* enhancement: PROCESS-STATUS now tracks stopped and continued processes
properly (also fixes lp#1624941, based on patch by Elias Pipping).
* bug fix: INSPECT handles errors signaled while printing slot
values. (lp#454682)
* bug fix: DESCRIBE works on classes like it used to.
* bug fix: *LOAD-PATHNAME* and *LOAD-TRUENAME* are bound to pathnames
when processing a sysinit or userinit file
* bug fix: save-lisp-and-die is able to collect more garbage on non-x86oid
gencgc targets.
* bug fix: fixed out-of-bounds array read in optimized POSITION on bit-vectors
* bug fix: signal emulation respects the 128-byte stack red zone on x86-64
macOS.