[rustdoc] Give more information into extracted doctest information
Follow-up of https://github.com/rust-lang/rust/pull/134531.
This update fragment the doctest code into its sub-parts to give more control to the end users on how they want to use it.
The new JSON looks like this:
```json
{
"format_version":2,
"doctests":[
{
"file":"$DIR/extract-doctests-result.rs",
"line":8,
"doctest_attributes":{
"original":"",
"should_panic":false,
"no_run":false,
"ignore":"None",
"rust":true,
"test_harness":false,
"compile_fail":false,
"standalone_crate":false,
"error_codes":[],
"edition":null,
"added_css_classes":[],
"unknown":[]
},
"original_code":"let x = 12;\nOk(())",
"doctest_code":{
"crate_level":"#![allow(unused)]\n",
"code":"let x = 12;\nOk(())",
"wrapper":{
"before":"fn main() { fn _inner() -> core::result::Result<(), impl core::fmt::Debug> {\n",
"after":"\n} _inner().unwrap() }",
"returns_result":true
}
},
"name":"$DIR/extract-doctests-result.rs - (line 8)"
}
]
}
```
for this doctest:
```rust
let x = 12;
Ok(())
```
With this, I think it matches what you need ``@ojeda?`` If so, once merged I'll update the patch I sent to RfL.
r? ``@aDotInTheVoid``
9bdf5d371f