Add `Function::fn_ptr_type(…)` for obtaining name-erased function type
The use case of this function if being able to group functions by their function ptr type.
cc `@flodiebold`
When viewing traces, it's slightly confusing when the span name doesn't
match the function name. Ensure the names are consistent.
(It might be worth moving most of these to use #[tracing::instrument]
so the name can never go stale. @davidbarsky suggested that is marginally
slower, so I've just done the simple change here.)
feature: Make generate function assist generate a function as a constructor if the generated function has the name "new" and is an asscociated function.
close#17050
This PR makes `generate function assist` generate a function as a constructor if the generated function has the name "new" and is an asscociated function.
If the asscociate type is a record struct, it generates the constructor like this.
```rust
impl Foo {
fn new() -> Self {
Self { field_1: todo!(), field_2: todo!() }
}
}
```
If the asscociate type is a tuple struct, it generates the constructor like this.
```rust
impl Foo {
fn new() -> Self {
Self(todo!(), todo!())
}
}
```
If the asscociate type is a unit struct, it generates the constructor like this.
```rust
impl Foo {
fn new() -> Self {
Self
}
}
```
If the asscociate type is another adt, it generates the constructor like this.
```rust
impl Foo {
fn new() -> Self {
todo!()
}
}
```
Support hovering limits for adts
Fix#17009
1. Currently, r-a supports limiting the number of struct fields displayed when hovering. This PR extends it to support enum variants and union fields. Since the display of these three (ADTs) is similar, this PR extends 'hover_show_structFields' to 'hover_show_adtFieldsOrVariants'.
2. This PR also resolved the problem that the layout of ADT was not restricted by display limitations when hovering on the Self type.
3. Additionally, this PR changes the default value of display limitations to `10` (instead of the original `null`), which helps users discover this feature.
