Rollup merge of #103774 - compiler-errors:dyn-trait-in-type-name, r=eholk
Format `dyn Trait` better in `type_name` intrinsic
Noticed this in #103764 (though not related to that PR at all!)
```rust
trait Foo {
type Bar;
}
fn main() {
println!(
"`dyn Fn(i32, i32) -> i32` => `{}`",
std::any::type_name::<dyn Fn(i32, i32) -> i32>()
);
println!(
"`dyn Foo<Bar = i32> + Send + Sync` => `{}`",
std::any::type_name::<dyn Foo<Bar = i32> + Send + Sync>()
);
}
```
```
`dyn Fn(i32, i32) -> i32` => `dyn core::ops::function::Fn<(i32, i32)>+Output = i32`
`dyn Foo<Bar = i32> + Send + Sync` => `dyn playground::Foo+Bar = i32+core::marker::Sync+core::marker::Send`
```
Just reuse `pretty_print_dyn_existential` which already makes an attempt to make its output stable.
bbd3a10663