Enable Link-Time Optimization (LTO) and evaluate other optimizations like Profile-Guided Optimization (PGO)

[zamazan4ik]

Hi!

I noticed that in the Cargo.toml file Link-Time Optimization (LTO) for the browser is not enabled. I suggest switching it on since it will reduce the binary size (always a good thing to have) and will likely improve the application's performance.

I suggest enabling LTO only for the Release builds to not sacrifice the developers' experience during the 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 release-lto profile where additionally to regular release optimizations LTO also will 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.

After enabling LTO I highly recommend evaluating using Profile-Guided Optimization (PGO) for the projects since it can measurably improve the project performance (much more information and benchmarks with PGO can be found in my repo: https://github.com/zamazan4ik/awesome-pgo) - this optimization is already enabled for all major web-browsers like Chromium-based browsers and Firefox. However, I am not sure that this work should be done at the current project stage - it's up to the project developers.

Thank you.

[wusyong]

Although we don't currently accept feature requests, this seems like a good first issue for a contribution.
I look forward to seeing anyone who wants to add an LTO profile to Verso.