[Bug]: Flaky test failures in `absl_failure_signal_handler_test` on ppc64le in Fedora

### Describe the issue

Recently, the [`abseil-cpp` package in Fedora](https://src.fedoraproject.org/rpms/abseil-cpp/) has been failing to build on `ppc64le` due to frequent flaky test failures in `absl_failure_signal_handler_test`.

Looking at the first failing builds in [Fedora 41](https://koschei.fedoraproject.org/build/19297765) and in [Rawhide / Fedora 42](https://koschei.fedoraproject.org/build/19372325), this *could* be associated with updating from kernel 6.11.3 to 6.12.4 in F41 and 6.13.0-0.rc3 to 6.13.0-0.rc4 in Rawhide, although there are other possibilities, and the flaky nature of the issue means that the the update that triggered this could have happened earlier.

### Steps to reproduce the problem

There are no particularly unusual compiler flags or patches in the [RPM spec file](https://src.fedoraproject.org/rpms/abseil-cpp/blob/33a4b5c72869e2a763fd39e8a80cd57788bc0eda/f/abseil-cpp.spec). I suspect you could reproduce this in a git checkout on any real `ppc64le` machine, but I can’t easily verify that because I don’t have *interactive* access to one.

-----

I tried the following on emulated `ppc64le` hardware – anyone can do this by running a `ppc64le` version of Fedora 41 via `qemu-user-system`; I used a [`mock` chroot](https://github.com/rpm-software-management/mock) with emulation via `qemu-user-static`.

```
$ git clone https://github.com/abseil/abseil-cpp.git
$ cd abseil-cpp
$ git checkout 20240722.0
$ cmake -S. -Bbuild -DABSL_BUILD_TESTING:BOOL=ON -DABSL_USE_EXTERNAL_GOOGLETEST:BOOL=ON -DABSL_FIND_GOOGLETEST:BOOL=ON
$ cmake --build build -j16 --verbose
$ ctest --test-dir build --output-on-failure --force-new-ctest-process -j16 --exclude-regex absl_symbolize_test
```

The `--exclude-regex absl_symbolize_test` is because `absl_symbolize_test` failed in emulation only, which I didn’t consider significant.

I was *not* able to reproduce this issue in emulation.

### What version of Abseil are you using?

20240722.0

### What operating system and version are you using?

Fedora 41 or Fedora Rawhide (future 42).

### What compiler and version are you using?

In Fedora 41:

```
Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ppc64le-redhat-linux/14/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: ppc64le-redhat-linux
Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,objc,obj-c++,ada,go,m2,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-targets=powerpcle-linux --disable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --enable-libstdcxx-backtrace --with-libstdcxx-zoneinfo=/usr/share/zoneinfo --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl=/builddir/build/BUILD/gcc-14.2.1-build/gcc-14.2.1-20240912/obj-ppc64le-redhat-linux/isl-install --enable-offload-targets=nvptx-none --enable-offload-defaulted --without-cuda-driver --enable-gnu-indirect-function --enable-secureplt --with-long-double-128 --with-long-double-format=ieee --with-cpu-32=power8 --with-tune-32=power8 --with-cpu-64=power8 --with-tune-64=power8 --build=ppc64le-redhat-linux --with-build-config=bootstrap-lto --enable-link-serialization=1
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.2.1 20240912 (Red Hat 14.2.1-3) (GCC)

```

In Fedora Rawhide:

```
Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ppc64le-redhat-linux/14/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: ppc64le-redhat-linux
Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,objc,obj-c++,ada,go,m2,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-targets=powerpcle-linux --disable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --enable-libstdcxx-backtrace --with-libstdcxx-zoneinfo=/usr/share/zoneinfo --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl=/builddir/build/BUILD/gcc-14.2.1-build/gcc-14.2.1-20241104/obj-ppc64le-redhat-linux/isl-install --enable-offload-targets=nvptx-none --enable-offload-defaulted --without-cuda-driver --enable-gnu-indirect-function --enable-secureplt --with-long-double-128 --with-long-double-format=ieee --with-cpu-32=power8 --with-tune-32=power8 --with-cpu-64=power8 --with-tune-64=power8 --build=ppc64le-redhat-linux --with-build-config=bootstrap-lto --enable-link-serialization=1
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.2.1 20241104 (Red Hat 14.2.1-6) (GCC)
```

### What build system are you using?

In Fedora 41, `cmake version 3.30.5`.

In Fedora Rawhide, `cmake version 3.31.3`.

### Additional context

While I don’t have *interactive* access to real `pp64le` hardware, I’m happy to test candidate patches or do experiments to get additional information by performing non-interactive `abseil-cpp` package “scratch” builds on Fedora infrastructure.

Just to be sure, and since I remember https://github.com/abseil/abseil-cpp/issues/1133, I tried building `abseil-cpp` with LTO disabled; this did not fix the problem.