8021: Enable searching for builtin types r=matklad a=Veykril Not too sure how useful this is for reference search overall, but for completeness sake it should be there  Also enables document highlighting for them. 8022: some clippy::performance fixes r=matklad a=matthiaskrgr use vec![] instead of Vec::new() + push() avoid redundant clones use chars instead of &str for single char patterns in ends_with() and starts_with() allocate some Vecs with capacity to avoid unnecessary resizing Co-authored-by: Lukas Wirth <lukastw97@gmail.com> Co-authored-by: Matthias Krüger <matthias.krueger@famsik.de>