m4-1.4.19.60-6ebfc: some core dumps

Just a preliminary error report:

==================================================
   GNU M4 1.4.19.60-6ebfc: tests/test-suite.log
==================================================

# TOTAL: 364
# PASS:  305
# SKIP:  57
# XFAIL: 0
# FAIL:  2
# XPASS: 0
# ERROR: 0

System information (uname -a): OpenBSD 7.0 GENERIC#2

.. contents:: :depth: 2

FAIL: test-c32isblank.sh
========================

test-c32isblank.c:109: assertion 'is == 0' failed
Abort trap (core dumped) 
FAIL test-c32isblank.sh (exit status: 1)

FAIL: test-c32isgraph.sh
========================

test-c32isgraph.c:161: assertion 'is != 0' failed
Abort trap (core dumped) 
FAIL test-c32isgraph.sh (exit status: 1)

------------------------------------------------------------
Note: there is also a third core file: test-c-stack.core

I will try to rebuild this with debugging enabled to see whether
it will crash then too and if so, use a debugger.

Please excuse this rather useless report - I've never even build
gnu m4 before.