make LLVM easyblock aware of amdgcn_capabilities build option

[Thyre]

Requires:

• Add support for amdgcn-capabilities configuration option and amdgcn_capabilities easyconfig parameter + related templates, similar to cuda-compute-capabilities easybuild-framework#4860

This allows building LLVM with AMD GPU support without requiring to adapt the LLVM EasyConfig beforehand. Deprecate amd_gfx_list, but still accept the value if the new build option is not set.

[Thyre]

LLVM 20.1.7 tests:

• {vis}[GCCcore/14.2.0] LLVM v20.1.7, Mesa v25.1.3, lit v18.1.8, ... easybuild-easyconfigs#23144 (comment) (Arch Linux, gfx1201)
• {vis}[GCCcore/14.2.0] LLVM v20.1.7, Mesa v25.1.3, lit v18.1.8, ... easybuild-easyconfigs#23144 (comment) (Rocky Linux 9, gfx90a & additional CUDA CCs defined)

[Thyre]

@Crivella can you take a quick look at this PR in the next few weeks? Would be great to have this merged quickly after the corresponding framework PR (and for ROCm-LLVM).

[Thyre]

With --amdgcn-capabilities=gfx1101

Test report by @Thyre

Overview of tested easyconfigs (in order)

• [...]
• SUCCESS LLVM-19.1.7-GCCcore-13.3.0.eb

Build succeeded for 47 out of 47 (1 easyconfigs in total)
zam226 - Linux Ubuntu 22.04, x86_64, 12th Gen Intel(R) Core(TM) i7-12700, Python 3.10.12
See https://gist.github.com/Thyre/c4e254b1cdb9a7b26878fdbec9c14c7e for a full test report.

[Thyre]

With --amdgcn-capabilities= (i.e no capability set)

Test report by @Thyre

Overview of tested easyconfigs (in order)

• SUCCESS LLVM-19.1.7-GCCcore-13.3.0.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
zam226 - Linux Ubuntu 22.04, x86_64, 12th Gen Intel(R) Core(TM) i7-12700, Python 3.10.12
See https://gist.github.com/Thyre/d563a82a488507609c6cfb9f7368e6ee for a full test report.

[Crivella]

@boegelbot please test @ jsc-zen3
EB_ARGS="LLVM-20.1.5-GCCcore-13.3.0.eb --installpath /tmp/$USER/ebpr-3824"
CORE_CNT=16

[boegelbot]

@Crivella: Request for testing this PR well received on jsczen3l1.int.jsc-zen3.fz-juelich.de

PR test command 'if [[ develop != 'develop' ]]; then EB_BRANCH=develop ./easybuild_develop.sh 2> /dev/null 1>&2; EB_PREFIX=/home/boegelbot/easybuild/develop source init_env_easybuild_develop.sh; fi; EB_PR=3824 EB_ARGS="LLVM-20.1.5-GCCcore-13.3.0.eb --installpath /tmp/$USER/ebpr-3824" EB_REPO=easybuild-easyblocks EB_BRANCH=develop /opt/software/slurm/bin/sbatch --job-name test_PR_3824 --ntasks="16" ~/boegelbot/eb_from_pr_upload_jsc-zen3.sh' executed!

• exit code: 0
• output:

Submitted batch job 7356

Test results coming soon (I hope)...

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Message to humans: this is just bookkeeping information for me,
it is of no use to you (unless you think I have a bug, which I don't).

[boegelbot]

Test report by @boegelbot

Overview of tested easyconfigs (in order)

• SUCCESS LLVM-20.1.5-GCCcore-13.3.0.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
jsczen3c1.int.jsc-zen3.fz-juelich.de - Linux Rocky Linux 9.5, x86_64, AMD EPYC-Milan Processor (zen3), Python 3.9.21
See https://gist.github.com/boegelbot/053bc8fde7d1ff5c596cde54c4985223 for a full test report.

[Crivella]

LGTM

[Crivella]

Going in, thanks @Thyre!