ci: enable IPO/LTO for nightly builds on selected jobs
Let's SKIP LTO in pre-merge (except Fedora build for now).
Let's DO LTO in nightly scheduled runs for every build (incl. these distributed to the runners).
Edit: this needs to be done fixing the jobs one by one. Let's switch what we have for now.
Deprecated: !20375 (closed)
ci: enable IPO/LTO for nightly builds
1. nightly takes a long, the extra few minutes for linking don't matter
2. nightly will run faster, since where it's CPU dependent it's at least +5% perf
3. it may reveal some painful areas of common code or driver.
Edited by David Heidelberg