Rustdoc search should use fuzzy searching in Return Type tab

[HeroicKatora]

Methods are only shown in 'In Return Type' results when their return types match the named type exactly. This is confusing as the normal search also works with any prefix and there is no indication that the other, similar looking tabs, would be stricter in their matching criteria. The title of course adds to the confusion as it directly suggests that fragments are considered.

For example:

https://docs.rs/wgpu/0.7.0/wgpu/struct.Device.html?search=CommandEncode#method.create_command_encoder

I expected to see this happen: The Device::create_command_encoder method should show up in the In Return Type search results. Note that when the name is completed to CommandEncoder the result is as expected:

Instead, this happened: There are two results in names, and no results for parameters or return types.

[HeroicKatora]

This is probably connected to another false negative with rather large detriments to discoverability of an API. Consider a type that only occur as part of a -> impl return type, as part of its bindings, such as -> impl Iterator<Item=Foo>. Then the method returning such an anonymous type can never be discovered through the search. One example is wgpu::Queue. It has a single way of construction, which returns an impl-Future.

Since there are no apparent methods constructing it, via search, one is left quite puzzled as to how one is supposed to ever create an instance ;) If it's a separate issue then feel free to fork or ping me.

[notriddle]

Fixed by #110371