pgo

Charlie Marsh 发现可以在 PGO 过程中构建的插桩二进制文件上使用 thin LTO，从而显著缩短构建时间，且最终二进制文件的性能似乎不受影响。

Nicholas Nethercote reports recent performance improvements to the Rust compiler, including a 5.59% mean wall-time reduction overall, major rustdoc speedups totaling 28%, and significant Clippy optimizations via PRs and PGO training changes.