Enable LTO on the release profile

[sorairolake]

This makes the binary smaller and may also improve performance.

• .rwxr-xr-x 16,163,864 root 11 Sep 18:37 target/release/xh # disabled (about 15 MiB)
• .rwxr-xr-x 11,236,416 root 11 Sep 18:42 target/release/xh # enalbed (about 11 MiB)

Add to Cargo.toml:

[profile.release]
lto = true

[blyxxyz]

Wow, that's a big improvement! Seems like a good idea.

What's the difference after also stripping debug symbols?

[sorairolake]

@blyxxyz I also tried when stripping, it was smaller than when LTO is disabled.

• 8.5 MiB (strip only)
• 7.2 MiB (LTO and strip)

[ducaale]

@sorairolake a 15% reduction in binary size is still an improvement. Would you mind creating a PR for it? Thanks

On a slightly related note, there is a nightly cargo feature that can automate stripping binaries. Once that stabilizes, we can remove the Strip release binary (linux and macOS) step from .github/workflows/release.yaml.