work around miscompilation of OpenBLAS on POWER by compiling with -fstack-protector-strong

[Flamefire]

(created using eb --new-pr)

Fix for the compiler issue reported at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100799 which leads to segfaults during the numpy tests on PPC.

Baseline: Broken at -O1, working at -Og

I got it to break with "-Og -fmove-loop-invariants".
Then it worked again by adding "-fstack-protector-all".

-fstack-protector-strong is cheap enough that you can (and perhaps should)
enable it almost always. Some distributions do this even?

See also a similar commit by @boegel to the BLAS/LAPACK libs contained in FlexiBLAS: b56f434

Supersedes #15867 and alternative to easybuilders/easybuild-framework#3809 / #13836

Fixes #12968

[Flamefire]

Build of SciPy-bundle-2021.05-foss-2021a.eb SciPy-bundle-2021.10-foss-2021b.eb prior to this PR:

Test report by @Flamefire
FAILED
Build succeeded for 0 out of 2 (2 easyconfigs in total)
taurusml2 - Linux RHEL 7.6, POWER, 8335-GTX (power9le), 6 x NVIDIA Tesla V100-SXM2-32GB, 440.64.00, Python 2.7.5
See https://gist.github.com/f171873ed92acbcd13cbbf92ddfc1c7f for a full test report.

[Flamefire]

Build of this PR:

Test report by @Flamefire
SUCCESS
Build succeeded for 2 out of 2 (2 easyconfigs in total)
taurusml2 - Linux RHEL 7.6, POWER, 8335-GTX (power9le), 6 x NVIDIA Tesla V100-SXM2-32GB, 440.64.00, Python 2.7.5
See https://gist.github.com/b8473ef08824d19fc4a59c8ee806167f for a full test report.

[Flamefire]

Build of SciPy-bundle-2021.05-foss-2021a.eb SciPy-bundle-2021.10-foss-2021b.eb after this PR:

Test report by @Flamefire
SUCCESS
Build succeeded for 2 out of 2 (2 easyconfigs in total)
taurusml2 - Linux RHEL 7.6, POWER, 8335-GTX (power9le), 6 x NVIDIA Tesla V100-SXM2-32GB, 440.64.00, Python 2.7.5
See https://gist.github.com/bffc9ba5e5c0406b5a27291f513055e4 for a full test report.

[boegel]

Looks good, I'll upload some test reports too for this, but should be good to go, thanks a lot for the effort here @Flamefire!

Do you think it's worth opening a PR for this upstream in the OpenBLAS repo?

[boegel]

Test report by @boegel
SUCCESS
Build succeeded for 12 out of 12 (12 easyconfigs in total)
fair-mastodon-c6g-2xlarge-0001 - Linux Rocky Linux 8.5, AArch64, ARM UNKNOWN (graviton2), Python 3.6.8
See https://gist.github.com/300bafb2e1ee5cd42d361cd924aa71c8 for a full test report.

[boegel]

Test report by @boegel
SUCCESS
Build succeeded for 12 out of 12 (12 easyconfigs in total)
node3131.skitty.os - Linux RHEL 8.4, x86_64, Intel(R) Xeon(R) Gold 6140 CPU @ 2.30GHz (skylake_avx512), Python 3.6.8
See https://gist.github.com/b84b8ba593585f7671e6d7a5a77d33d3 for a full test report.

[boegel]

Test report by @boegel
SUCCESS
Build succeeded for 13 out of 13 (12 easyconfigs in total)
easybuild2.novalocal - Linux CentOS Stream 8, POWER, IBM pSeries (emulated by qemu) (power9le), Python 3.6.8
See https://gist.github.com/7b8c84272f997cda37549655f82ac1aa for a full test report.

[boegel]

Going in, thanks @Flamefire!