GH-50930: Prevent symbol interposition in arrow_s3fs

[tadeja]

Rationale for this change

Fix #50930 Actual: "Invalid: Attempt to initialize S3 after it has been finalized"
[ FAILED ] S3Test.FromUriRejectsUnknownOptions (0 ms)

Both libarrow.so and dynamically loaded libarrow_s3fs.so compile s3fs.cc, so both libraries get own S3 state and filesystem registration callbacks.
The S3 module tests finalize the state in libarrow.so before loading libarrow_s3fs.so. ELF symbol interposition causes libarrow_sf3s.so references to bind to definitions in libarrow.so, so the module incorrectly reuses its finalized state.
LD_DEBUG=bindings example output (for symbol arrow::fs::kS3FileSystemModule):

12833:	binding file /build/cpp/debug/libarrow_s3fs.so [0] to /build/cpp/debug/libarrow.so.2600 [0]: normal symbol `_ZN5arrow2fs19kS3FileSystemModuleE'

These duplicate definitions were present before, but the issue was masked by -fvisibility-inlines-hidden by conda-forge compilers 1.11 (with gcc 14.4).
Now with conda-forge compilers 2.0 there is no -fvisibility-inlines-hidden anymore, minimally activated as described in conda-forge/conda-forge.github.io#2595.

What changes are included in this PR?

Link arrow_s3fs with -Wl,-Bsymbolic-functions so its function references bind locally,
and make kS3FileSystemModule static so it's not exported.

Are these changes tested?

Yes, S3Test.FromUriRejectsUnknownOptions passes.

Are there any user-facing changes?

No.

• GitHub Issue: [C++][CI] S3 tests fail with "Attempt to initialize S3 after it has been finalized" #50930

[github-actions]

⚠️ GitHub issue #50930 has been automatically assigned in GitHub to PR creator.

[Copilot]

Pull request overview

Fixes ELF symbol interposition that could cause arrow_s3fs to reuse finalized S3 state from libarrow.

Changes:

• Makes the S3 filesystem registrar local.
• Detects linker support and applies -Bsymbolic-functions to arrow_s3fs.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
cpp/src/arrow/filesystem/s3fs.cc	Localizes the S3 registrar.
cpp/src/arrow/CMakeLists.txt	Applies symbolic function binding to the S3 module.
cpp/CMakeLists.txt	Detects linker support for the required option.

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[pitrou]

Both libarrow.so and dynamically loaded libarrow_s3fs.so compile s3fs.cc

Isn't that the actual problem? I don't think we should compile the same file twice. @raulcd