libgcobol: Allow for lack of LOG_PERROR

libgcobol: Allow for lack of LOG_PERROR

The libgcobol build is broken again on Solaris:

/vol/gcc/src/hg/master/local/libgcobol/libgcobol.cc: In function ‘void
default_exception_handler(ec_type_t)’:
/vol/gcc/src/hg/master/local/libgcobol/libgcobol.cc:11196:44: error:
‘LOG_PERROR’ was not declared in this scope; did you mean ‘LOG_ERR’?
11196 | static int priority = LOG_INFO, option = LOG_PERROR, facility =
LOG_USER;
      |                                            ^~~~~~~~~~
      |                                            LOG_ERR
/vol/gcc/src/hg/master/local/libgcobol/libgcobol.cc:11202:28: error:
‘facility’ was not declared in this scope
11202 |     openlog(ident, option, facility);
      |                            ^~~~~~~~

LOG_PERROR is a BSD extension not present on Solaris due to its System V
heritage, and Linux syslog(3) documents:

       LOG_PERROR     (Not in POSIX.1-2001 or  POSIX.1-2008.)   Also  log  the
                      message to stderr.

This patch provides a fallback definition, just the minimum to unbreak
the build.

Tested on amd64-pc-solaris2.11, sparcv9-sun-solaris2.11, and
x86_64-pc-linux-gnu.

2025-05-12  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	libgcobol:
	* libgcobol.cc [!LOG_PERROR] (LOG_PERROR): Provide fallback.