[capture-promotion] Update style of old pass.

No one has touched this pass in years and I am going to do a little work in it
to help with concurrency. So I am formatting the pass before I make further
changes.

All I did was I renamed CamelCase -> camelCase and git-clang-format the diff. I
used clangd to incrementally perform the renaming using some integration into my
editor.

Author: gottesmm