[PGO] Provide Pre-Generated Profiles

Feature or enhancement

PGO (Profile-Guided Optimization) offers significant performance benefits for Python. However, the current approach has a drawback: it makes the builds non-reproducible.

This issue could be resolved if upstream provided pre-generated profiles (perhaps via CI pipelines). These profiles could then be included in the distributed tarball, similar to how Chromium handles it. By doing so, distributions wouldn't need to:

1. Compile the source code twice.
2. Perform profiling themselves.
   In addition to streamlining the process for maintainers, this would also help maintain package reproducibility—a key consideration for many distributions.

I am not sure, about the integration with GCC, since in my testing the compilation failed with a preset profile (but I didnt dig deeper into this yet.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

尚未确定任何文件、测试或入口点。首先调查 CPython 的 PGO 构建和 CI 流水线，尤其是 GCC 如何使用预设 profile。完成的标准是在 CI 中生成可复现的 profile，并将其包含在分发的 tarball 中，同时无需下游进行 profiling 或再次编译。