shells/bosh: Update to 20201009

New features with AN-2020-09-04:
- autoconf: congig.guess: FreeBSD on 64 bit ARM returns arm64 from
  uname -m; this was previously not supported and rejected by config.sub.
  We now convert "arm64" into "aarch64" in config.guess to get the usual
  expected results.

- Makefile system: RULES/rules.env The environment variables FIGNORE,
  LD_LIBRARY_PATH LD_LIBRARY_PATH_32 and LD_LIBRARY_PATH_64 are now
  unexported from the enviroment.

  In special FIGNORE is dangerous, as it is frequently used by bash
  users but tells ksh93 to modify it's behavior with "echo *" and
  this may cause strange things with our makefiles in case that
  /bin/sh is ksh92. This applies e.g. to Oracle Solaris 11 and
  OpenSolaris.

- Bourne Shell: added $(RM) -f $(DEST_DIR)$(INSBASE)/xpg4/bin/bosh
  to the Makefile in the commands before creating the symlink
  xpg4/bin/bosh to bosh to permit to call "make install" more than
  once without causing an error.

- Bourne Shell: version.h now contains a new version date.

New features with AN-2020-10-09:
- autoconf: Added support for newer HP-UX versions on Itanium.

  Thanks to Rudi Blom for reporting and making a change proposal.

- Bourne Shell: The "wait" builtin is now POSIX compliant and returns 127
  in $? in case that a process id to be waited for does not exist.

- Bourne Shell: The exit code retrieved by $/ no longer is masked by 0xFF
  when this code originates from a wait(1) call.

  Thanks to Koichi Nakashima for reporting

- Bourne Shell: The man page has been enhanced for a better description
  of the exit code constraitns.

  Thanks to Koichi Nakashima for reporting

- Bourne Shell: The exit code from background jobs is now kept until
  the builtin wait(1) is called.

  Note that this introduces the need to call "wait" from time to time
  in order to free shell job management resources.

  Thanks to Koichi Nakashima for reporting

- Bourne Shell: The changes to keep exit codes for background jobs
  caused problems that triggered a SIGSEGV in the shell with jobs like:

      (sleep 10; exit 17)&

  This needed a restructuring in the job management implementation.

- Bourne Shell: Since the next POSIX standard will make it optional
  whether sig2str() and str2sig() deal with entries for "EXIT" / 0,
  we enhanced the trap2str() and str2trap() interfaces to handle
  "EXIT" / 0 and now call these functions before sig2str() and
  str2sig().

- Bourne Shell: a new version date has been created.


(micha)