Rollup merge of #81459 - probablykasper:text-selection-fix, r=Nemo157
Rollup merge of #81459 - probablykasper:text-selection-fix, r=Nemo157

Fix rustdoc text selection for page titles

Fixes text selection of page titles by placing the `h1.fqn span.in-band` element before `h1.fqn span.out-of-band`.

Before vs after:
https://user-images.githubusercontent.com/11315492/105768203-55708700-5f5c-11eb-924b-4e7527ffe147.mp4

Retry of PR #81397 due to merge conflicts confusing me. Recreated the same changes as in that PR, but now when I run `./x.py doc library/std`, no changes I make to `src/librustdoc/html/render/mod.rs` to the file are reflected in the built doc files, even if I delete the `build` folder. I'm guessing there's some cache I'm missing?

r? `@Nemo157`

graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust