Tests: Teach RunCMake to ignore GNU ld --warn-rwx-segments warnings
GNU ld 2.39 added warnings of the form
ld: warning: %pB has a LOAD segment with RWX permissions
They appear when linking test binaries on `hppa` and `sparc`.
Debian-Issue: https://bugs.debian.org/1098956
Debian-Issue: https://bugs.debian.org/1098970