Inline code has collapsed whitespace

[mgeisler]

Code

When documenting the handling of whitespace in the textwrap crate, I noticed that whitespace is collapsed in inline code. That is,

`"   foo   "`

is rendered the same as

`" foo "`

Test it with

$ cargo new --lib whitespace && cd whitespace && echo '//! `"   foo   "`' > src/lib.rs && cargo doc --open

Version it worked on

It worked on Rust 1.50:

Version with regression

It stopped working on Rust 1.51. I tracked down the change to #81558, which removed white-space: pre-wrap from the CSS. The page now looks like this:

[pickfire]

Note that a fix here could potentially create a regression for ascii art on mobile. Need to double check the vec page.

[camelid]

Assigning P-high and removing I-prioritize as discussed in the prioritization working group.

@rustbot label: +P-high -I-prioritize