toolchain/59710: gcc14 update broke several tests

[campbell+netbsd%mumble.net@localhost]

>Number:         59710
>Category:       toolchain
>Synopsis:       gcc14 update broke several tests
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Oct 18 20:25:01 +0000 2025
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
The NetGCC14 Foundabug
>Environment:
>Description:
build: OK with 585517 lines of log, install: OK, tests: 10418 passed, 676 skipped, 105 expected_failure, 2 failed, ATF output: raw, xml, html
no longer failing: fs/vfs/t_renamerace/lfs_renamerace_dirs, net/if_wg/t_misc/wg_rekey, new failures: lib/librumpclient/t_exec/threxec
commit 2025.10.07.06.45.32 mrg src/external/gpl3/gcc/README.gcc14 1.23
commit 2025.10.07.06.45.32 mrg src/share/mk/bsd.own.mk 1.1440
build: OK with 586547 lines of log, install: OK, tests: 10414 passed, 676 skipped, 105 expected_failure, 6 failed, ATF output: raw, xml, html
no longer failing: lib/librumpclient/t_exec/threxec, new failures: fs/vfs/t_renamerace/lfs_renamerace_cycle, fs/vfs/t_renamerace/lfs_renamerace_dirs, usr.bin/c++/t_call_once/call_once_pic_profile, usr.bin/c++/t_cxxruntime/cxxruntime_pic_profile, usr.bin/c++/t_static_destructor/static_destructor_pic_profile

Three of these tests remain persistently broken:

- usr.bin/c++/t_call_once/call_once_pic_profile
- usr.bin/c++/t_cxxruntime/cxxruntime_pic_profile
- usr.bin/c++/t_static_destructor/static_destructor_pic_profile

(The lfs tests appear to be flaky and were intermittently failing before the gcc14 update too.)
>How-To-Repeat:
cd /usr/tests/usr.bin/c++ && atf-run | atf-report
>Fix:
Yes, please!