FWIW I never encountered 'tree shaking' in the C/C++ world (only in the Javascript world). Commonly in the C/C++ world, dead-code-elimination is used for anything that removes (or ignores in the first place) unused code and data.

And I think with LTO it's all the same anyway (in the past there were a lot of gnarly details how the compiler/librarian actually created a static link library to avoid linking code that's not actually used, but that all doesn't matter anymore with LTO).