Build failure of m4 on hppa

Hello again.

Additionally, m4 1.4.20 fails to build on hppa:

FAIL: test-c-stack.sh
=====================

FAIL test-c-stack.sh (exit status: 1)

FAIL: test-sigsegv-catch-stackoverflow1
=======================================

FAIL test-sigsegv-catch-stackoverflow1 (exit status: 139)

FAIL: test-sigsegv-catch-stackoverflow2
=======================================

Starting recursion pass 1.
Stack overflow 1 missed.
FAIL test-sigsegv-catch-stackoverflow2 (exit status: 1)

Full build log here:

https://buildd.debian.org/status/fetch.php?pkg=m4&arch=hppa&ver=1.4.20-2&stamp=1759596994&raw=0

Thanks.