Rollup merge of #134880 - as1100k-forks:fix-rustdoc-json-path-name, r=aDotInTheVoid

Made `Path::name` only have item name rather than full name

Closes #134853

This PR makes `Path::name` to only have item name rather than full name, i.e. with the following code

```rust
pub mod foo {
    pub struct Bar;
}

pub fn get_bar() -> foo::Bar {
    foo::Bar
}
```
and running `./rustdoc ./demo.rs -wjson -Zunstable-options` gives:
```json
{
    "41": {
        "id": 41,
        "name": "get_bar",
        "inner": {
            "function": {
                "sig": {
                    "inputs": [],
                    "output": {
                        "resolved_path": {
                            "name": "Bar",
                            "id": 0,
                            "args": { "angle_bracketed": { "args": [], "constraints": [] }
                            }
                        }
                    }
                }
            }
        }
    }
}
```
_Information which isn't useful here was trimmed_

r? aDotInTheVoid

src/librustdoc/json/conversions.rs

@@ -622,7 +622,7 @@ impl FromClean<clean::Type> for Type {
 impl FromClean<clean::Path> for Path {
     fn from_clean(path: clean::Path, renderer: &JsonRenderer<'_>) -> Path {
         Path {
-            name: path.whole_name(),
+            name: path.last_opt().map_or(String::from(""), |s| String::from(s.as_str())),
             id: renderer.id_from_item_default(path.def_id().into()),
             args: path.segments.last().map(|args| Box::new(args.clone().args.into_json(renderer))),
         }

src/rustdoc-json-types/lib.rs

@@ -30,7 +30,7 @@ pub type FxHashMap<K, V> = HashMap<K, V>; // re-export for use in src/librustdoc
 /// This integer is incremented with every breaking change to the API,
 /// and is returned along with the JSON blob as [`Crate::format_version`].
 /// Consuming code should assert that this value matches the format version(s) that it supports.
-pub const FORMAT_VERSION: u32 = 37;
+pub const FORMAT_VERSION: u32 = 38;
 
 /// The root of the emitted JSON blob.
 ///

tests/rustdoc-json/return_private.rs

@@ -6,7 +6,7 @@ mod secret {
 }
 
 //@ has "$.index[*][?(@.name=='get_secret')].inner.function"
-//@ is "$.index[*][?(@.name=='get_secret')].inner.function.sig.output.resolved_path.name" \"secret::Secret\"
+//@ is "$.index[*][?(@.name=='get_secret')].inner.function.sig.output.resolved_path.name" \"Secret\"
 pub fn get_secret() -> secret::Secret {
     secret::Secret
 }