Enable LTO by default

As I've said the first time this was floated, I'm ok with this one. Just a question, are there any security considerations when using LTO?

No security concerns that I am aware of. It only extends optimization from single file at a time to multiple files at once.

LTO increases GDB's memory use: https://sourceware.org/bugzilla/show_bug.cgi?id=23710

By something like an order of magnitude? I've OOM'd recently (with 32G of RAM) trying to get a backtrace of nm-connection-editor with the app, GLib and GTK3 built with LTO and -g3.

-flto=auto would be nice but Clang chokes on it.

resolved all threads

added 2 commits

• 33d8b5fd - 1 commit from branch archlinux:master
• 5925694a - Enable LTO by default

Compare with previous version

For more information, Ubuntu 21.04 will enable lto by default and LTO wiki page with more info

added 4 commits

• 5925694a...a7a94d35 - 3 commits from branch archlinux:master
• 6a50f396 - Enable LTO by default

Compare with previous version

merged