fix(llvm,llvm20): correct clang's default GCC triple for Azure Linux stage2

[rlmenge]

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• The toolchain has been rebuilt successfully (or no changes were made to it)
• The toolchain/worker package manifests are up-to-date
• Any updated packages successfully build (or no packages were changed)
• Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• All package sources are available
• cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• LICENSE-MAP files are up-to-date (./LICENSES-AND-NOTICES/SPECS/data/licenses.json, ./LICENSES-AND-NOTICES/SPECS/LICENSES-MAP.md, ./LICENSES-AND-NOTICES/SPECS/LICENSE-EXCEPTIONS.PHOTON)
• All source files have up-to-date hashes in the *.signatures.json files
• sudo make go-tidy-all and sudo make go-test-coverage pass
• Documentation has been updated to match any changes to the build system
• Ready to merge

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Summary

Fix clang/clang20 stage2 bootstrap failures caused by clang’s generated default GCC triple pointing at the Fedora/RHEL-style runtime path.

Both llvm and llvm20 generate clang config files containing:

--gcc-triple=%{_target_cpu}-redhat-linux

In Azure Linux stage2, GCC runtime files are installed under the Azure Linux vendor triple instead:

/usr/lib/gcc/%{_target_cpu}-%{_vendor}-linux/

This mismatch causes clang-driven links to fail when looking for crtbeginS.o, libgcc, and libgcc_s. That affects both the primary LLVM toolchain and the llvm20 compatibility toolchain during
stage2/self-bootstrap builds, and can also break downstream packages that link through clang.

This change updates both llvm and llvm20 to:

• Generate clang/clang20 default configs with %{_target_cpu}-%{_vendor}-linux.
• Add a temporary bootstrap clang config during %build so the current self-rebuild overrides the stale clang config already present in the buildroot.
• Wrap the instrumented clang used during PGO profile generation so generate-profdata also uses the corrected GCC triple.
• Disable %check by default because OpenMP tests are unreliable under systemd-nspawn due to missing /proc/sys/kernel tunables and restricted cgroup/thread support.

The %build bootstrap config injection and PGO clang wrapper are intended as temporary workarounds. The plan is to remove them once stage2 reaches a stable state where a usable clang with the corrected default config is already available in the buildroot.

Change Log

• Correct clang and clang20 default GCC triple from *-redhat-linux to *-%{_vendor}-linux.
• Add matching llvm and llvm20 bootstrap workarounds using --config=/tmp/azl-clang-bootstrap.cfg.
• Apply the bootstrap config to the PGO instrumented clang wrapper for both toolchains.
• Disable %check by default for both llvm and llvm20.
• Regenerate specs, macro files, and lock fingerprints for both components.

Associated issues

• https://dev.azure.com/mariner-org/mariner/_workitems/edit/19791

Test Methodology

Validated both llvm and llvm20 through Koji stage2 builds.

• llvm20 Koji task/build: 2337113
• llvm Koji task/build: 2337114
  Both Koji builds completed successfully and produced the expected clang/LLVM/lld RPMs.

[azureuser@rlmenge-azl4-arm64 clang-test-17100]$ rpm -qa | grep llvm
llvm-filesystem-21.1.8-6.azl4.aarch64
llvm-libs-21.1.8-6.azl4.aarch64
llvm-21.1.8-6.azl4.aarch64
[azureuser@rlmenge-azl4-arm64 clang-test-17100]$ clang --version
clang version 21.1.8 (Microsoft Corporation 21.1.8-6.azl4)
Target: aarch64-azurelinux-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Configuration file: /etc/clang/aarch64-azurelinux-linux-gnu-clang.cfg
[azureuser@rlmenge-azl4-arm64 clang-test-17100]$

[Copilot]

Pull request overview

This PR updates the LLVM (llvm, llvm20) packaging to fix Azure Linux stage2 bootstrap/self-rebuild failures caused by clang’s default GCC triple pointing at the wrong vendor runtime path.

Changes:

• Update clang/clang20 default config generation to use %{_target_cpu}-%{_vendor}-linux instead of *-redhat-linux.
• Add stage2 bootstrap workarounds (temporary /tmp clang config injection and a PGO perf-training clang wrapper) to force the corrected GCC triple during the self-rebuild.
• Disable %check by default for llvm/llvm20 and regenerate rendered specs/macros + refresh lock fingerprints.

Reviewed changes

Copilot reviewed 7 out of 9 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
specs/l/llvm/llvm.spec	Rendered spec updated: corrected gcc triple in clang config, added bootstrap config injection + PGO wrapper, default %check disabled.
specs/l/llvm/llvm.azl.macros	Generated azldev macros updated to include %_without_check 1.
specs/l/llvm20/llvm20.spec	Rendered spec updated: adds macros load/source, corrected gcc triple in clang20 config, adds bootstrap config injection + PGO wrapper, default %check disabled.
specs/l/llvm20/llvm20.azl.macros	New generated azldev macros file (disables check + mlir by default).
base/comps/llvm/llvm.comp.toml	Component config adds overlays/workarounds for gcc triple + bootstrap/PGO wrapper; disables check/mlir via build.without.
base/comps/llvm20/llvm20.comp.toml	New component config for llvm20 with the same overlays/workarounds; disables check/mlir via build.without.
base/comps/components.toml	Removes inline [components.llvm20] entry now that llvm20 has a dedicated .comp.toml.
locks/llvm.lock	Updates input fingerprint to match component config changes.
locks/llvm20.lock	Updates input fingerprint to match new component config + overlays.