[PATCH] D28746: Mention ThinLTO with PGO in ReleaseNotes 4.0

[Piotr Padlewski via Phabricator via cfe-commits]

Prazek marked 2 inline comments as done.
Prazek added a comment.

Cool, This still might require some small fixes - I haven't generate docs for it, so I will check it before release.


https://reviews.llvm.org/D28746