"USE BEFORE" is seen to generate SIGSEGV

[rdubner]

This source code:

       Identification Division.
       Program-Id. rtest.
       Procedure Division.
       DeptHdrUse Section.
           Use Before Reporting DeptHdr.

results in a cobc SIGSEGV under these conditions:

bob@doobie:~/repos/cbl-gdb-samples/ref_test_23$ uname -a
Linux doobie 4.15.0-142-generic #146-Ubuntu SMP Tue Apr 13 01:11:19 UTC 2021
x86_64 x86_64 x86_64 GNU/Linux

bob@doobie:~/repos/cbl-gdb-samples/ref_test_23$ head -n2 /etc/os-release
NAME="Ubuntu"
VERSION="18.04.5 LTS (Bionic Beaver)"

bob@doobie:~/repos/cbl-gdb-samples/ref_test_23$ cobc -version
cobc (GnuCOBOL) 3.1.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Keisuke Nishida, Roger While, Ron Norman, Simon Sobisch, Edward
Hart
Built     Apr 15 2021 08:36:56
Packaged  Dec 23 2020 12:04:58 UTC
C version "7.5.0"

bob@doobie:~/repos/cbl-gdb-samples/ref_test_23$ cobc rtest.cbl
rtest.cbl: in section 'DeptHdrUse':
rtest.cbl:5: error: 'DeptHdr' is not defined

attempt to reference unallocated memory (signal SIGSEGV)

cobc: aborting compile of rtest.cbl at line 5 (PROGRAM-ID: rtest)
cobc: Please report this!