/cc @Araq @krux02

• this PR manually squashes implement sizeof and alignof operator #5664 to avoid messing git history (so a fast fwd merge can happen);

• manually squashed + rebased as follows:

git fetch origin pull/5664/head:pr_5664
git checkout pr_5664
git merge origin/devel
git checkout pull_5664_3 -b origin/devel
git checkout pr_5664 -- `git diff --name-only pr_5664`
# give proper attribution it to @krux02
git commit --amend --author="Arne Döring <[email protected]>"

EDIT for this to be attributed to original PR author, looks like the resulting squashed PR needs to be merged in github via "merge commit" or "rebase merging"; "squash" would overwrite the author field with the committer.