[Feature Request] Enable Link-Time Optimization (LTO)

[zamazan4ik]

Describe the problem/motivation

Motivation: improve the binary size and, possibly, gain a bit of additional performance (but the binary size is the main motivation in this case).

Describe the solution you'd like

I suggest enabling LTO only for the Release builds so as not to sacrifice the developers' experience while working on the project since LTO consumes an additional amount of time to finish the compilation routine. If you think that a regular Release build should not be affected by such a change as well, then I suggest adding an additional dist or release-lto profile where additionally to regular release optimizations LTO will also be added. Such a change simplifies life for maintainers and others interested in the project persons who want to build the most performant version of the application. Using ThinLTO should also help to reduce the build-time overhead with LTO. If we enable it on the Cargo profile level, users, who install the application with cargo install, will get the LTO-optimized version "automatically". E.g., check cargo-outdated Release profile.

Basically, it can be enabled with the following lines:

[profile.release]
lto = true

I have made quick tests on my local setup (Fedora 40, Rustc 1.82): enabling lto = true for the Release profile reduces the binary size from 28 Mib to 20 Mib.

Alternatives considered

Leave the things as is