Allow restricting search results to come from a subset of crates #130971
Description
When docs are built for a set of crates (e.g. https://doc.rust-lang.org/nightly/nightly-rustc/), it's easy to find yourself looking at a wide collection of crates.
AFAIK there's currently no way to restrict searches from a subset of crates. The dropdown for filtering crates is a single-choice dropdown. I run into this quite often, in that I usually have a vague idea of which compiler crates the thing I'm looking for is in, but I do not know exactly which compiler crate. It would be very helpful to me if it's possible to filter on multiple crates.
Apologies if this has been brought up before, I couldn't find a similar issue in the issue tracker based on naive searches.