changes in sbcl-1.5.3 relative to sbcl-1.5.2:
* platform support:
- RISC-V: numerous bug fixes and improvements
- all platforms: better run-program performance when used from multiple
threads.
* enhancement: (declaim (optimize (debug 2))) ensures compilation of
top-level forms, providing better debugging for simple forms that are
otherwise "byte-code interpreted" when compiled into FASLs.
* bug fix: use of finalizers could in rare circumstances cause a crash in
the garbage collector.
* bug fix: show extended function designators, e.g. (setf foo), in the
disassembler
* optimization: reduced overhead of calling NTH/NTHCDR.
* optimization: improved FLOAT-SIGN on DOUBLE-FLOATs on 64-bit platforms