internal: Migrate assists to the structured snippet API, part 4
Continuing from #15260
Migrates the following assists:
- `add_turbo_fish`
- `add_type_ascription`
- `destructure_tuple_binding`
- `destructure_tuple_binding_in_subpattern`
I did this a while ago, but forgot to make a PR for the changes until now. 😅
Due to the way the current tree mutation api works, we need to collect
changes before we can apply them to the real syntax tree, and also can only
switch to a file once.
`destructure_tuple_binding_in_sub_pattern` also gets migrated even
though can't be used.
feat: Bool to enum assist
This adds the `bool_to_enum` assist, which converts the type of boolean local variables, fields, constants and statics to a new `enum` type, making it easier to distinguish the meaning of `true` and `false` by renaming the variants.
Closes#14779
the "add missing members" assists: implemented substitution of default values of const params
To achieve this, I've made `hir::ConstParamData` store the default values
internal : rewrite DeMorgan assist
fixes#15239 , #15240 . This PR is a rewrite of the DeMorgan assist that essentially rids of all the string manipulation and modifies syntax trees to apply demorgan on a binary expr. The main reason for the rewrite is that I wanted to use `Expr::needs_parens_in` method to see if the expr on which the assist is applied would still need the parens it had once the parent expression's operator had equal precedence with that of the expression. I used `.clone_(subtree|for_update)` left and right and probably more than I should have, so I would also be happy to hear how I could have prevented redundant cloning.
Added remove unused imports assist
This resolves the most important part of #5131. I needed to make a couple of cosmetic changes to the search infrastructure to do this.
A few open questions:
* Should imports that don't resolve to anything be considered unused? I figured probably not, but it would be a trivial change to make if we want it.
* Is there a cleaner way to make the edits to the use list?
* Is there a cleaner way to get the list of uses that intersect the current selection?
* Is the performance acceptable? When testing this on itself, it takes a good couple seconds to perform the assist.
* Is there a way to hide the rustc diagnostics that overlap with this functionality?
