Scope libatomic allowance to MIPS on Python 3.13

[zanieb]

Addressing the initial feedback in #410

[indygreg]

Thank you.

A proper solution here might be to statically link libatomic. But that can be done separately.

[zanieb]

Thanks for giving it a look

A proper solution here might be to statically link libatomic. But that can be done separately.

Agreed. I've started looking into that, but after engaging upstream (python/cpython#127708 (comment)) I'm starting to wonder about the value of the MIPS distributions?

[indygreg]

Let's merge this since it fixes the PYTHON.json metadata advertisement for libatomic.so on Linux (which is wrong). We can discuss MIPS elsewhere.

[indygreg]

Also, extension-modules.yml has the reference to libatomic regarding OpenSSL I was thinking ok:

_hashlib:
  sources:
    - _hashopenssl.c
  includes-deps:
    - include
  links:
    - crypto
  links-conditional:
    # Clang built OpenSSL 3.x depends on libatomic. We force linking against
    # a static library so there isn't a runtime dependency.
    - name: ':libatomic.a'
      targets:
        - i686-unknown-linux-gnu
        - mips-unknown-linux-gnu
        - mipsel-unknown-linux-gnu
        - x86_64.*-unknown-linux-gnu

We could change the build-cpython.sh script to statically link libatomic.a.

[zanieb]

Yeah I was looking at that implementation to guide how to hide the symbol and force it to statically link 👍