GH-144552: Clean up tail-call.yml CI

[savannahostrowski]

• Issue: Refactor tail-call.yml  #144552

[Fidget-Spinner]

Thanks for this!

[hugovk]

Is this clang-20 also the LLVM number? (in three places)

-CC=clang-20 ...
+CC=clang-${{ matrix.llvm }} ...

[hugovk]

Is this clang-20 also the LLVM number? (in three places)

-CC=clang-20 ...
+CC=clang-${{ matrix.llvm }} ...

Included in savannahostrowski#15, which also combines the Linux steps.

[hugovk]

savannahostrowski#16 combines two Windows steps.

That will leave us with these Windows jobs:

#          - target: i686-pc-windows-msvc/msvc
#            architecture: Win32
#            runner: windows-2022
          - target: x86_64-pc-windows-msvc/msvc
            architecture: x64
            runner: windows-2025-vs2026
            build_flags: ""
            run_tests: true
          - target: x86_64-pc-windows-msvc/msvc-free-threading
            architecture: x64
            runner: windows-2025-vs2026
            build_flags: --disable-gil
            run_tests: false
#          - target: aarch64-pc-windows-msvc/msvc
#            architecture: ARM64
#            runner: windows-2022

Note Win32 and ARM64 are commented out, and have been since initial commit exactly one year ago! 🎂 cb640b6

Only Windows x64 architecture is run. I suggest we delete the commented code, we can re-add it when we're ready.

And after combining two of the three Windows steps into one, we have two remaining:

      - name: Native Windows MSVC (release)
        if: runner.os == 'Windows' && matrix.architecture != 'ARM64'
        shell: pwsh
        run: |
          $env:PlatformToolset = "v145"
          ./PCbuild/build.bat --tail-call-interp ${{ matrix.build_flags }} -c Release -p ${{ matrix.architecture }}
          if ("${{ matrix.run_tests }}" -eq "true") {
            ./PCbuild/rt.bat -p ${{ matrix.architecture }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3
          }

      # No tests (yet):
      - name: Emulated Windows Clang (release)
        if: runner.os == 'Windows' && matrix.architecture == 'ARM64'
        shell: pwsh
        run: |
          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.0
          $env:PlatformToolset = "clangcl"
          $env:LLVMToolsVersion = "${{ matrix.llvm }}.1.0"
          $env:LLVMInstallDir = "C:\Program Files\LLVM"
          ./PCbuild/build.bat --tail-call-interp -p ${{ matrix.architecture }}

I don't think that second one has ever been run? I suggest we delete that too. And when we're ready, we can re-add as needed. And that might be by combining into the first Windows step instead of a standalone one.

The && matrix.architecture != 'ARM64' guard in this first step is also redundant and can be deleted.

[savannahostrowski]

Thanks for the pulls @hugovk! I was initially trying to be somewhat conservative but I'm inclined to remove the unused job and commented out platforms as well. I think it'll be obvious enough if/when we need to add them back in.

[chris-eibl]

Maybe it is now time to switch to 21 like is used for the jit stencils?

[chris-eibl]

On Linux free-threading the tests are run. Shall we save CI resources there, too, or play safe here and run the tests?