Rollup merge of #72233 - dtolnay:literal, r=petrochenkov
Fix {:#?} representation of proc_macro::Literal
Before:
```rust
TokenStream [
Ident {
ident: "name",
span: #0 bytes(37..41),
},
Punct {
ch: '=',
spacing: Alone,
span: #0 bytes(42..43),
},
Literal { lit: Lit { kind: Str, symbol: "SNPP", suffix: None }, span: Span { lo: BytePos(44), hi: BytePos(50), ctxt: #0 } },
Punct {
ch: ',',
spacing: Alone,
span: #0 bytes(50..51),
},
Ident {
ident: "owner",
span: #0 bytes(56..61),
},
Punct {
ch: '=',
spacing: Alone,
span: #0 bytes(62..63),
},
Literal { lit: Lit { kind: Str, symbol: "Canary M Burns", suffix: None }, span: Span { lo: BytePos(64), hi: BytePos(80), ctxt: #0 } },
]
```
After:
```rust
TokenStream [
Ident {
ident: "name",
span: #0 bytes(37..41),
},
Punct {
ch: '=',
spacing: Alone,
span: #0 bytes(42..43),
},
Literal {
kind: Str,
symbol: "SNPP",
suffix: None,
span: #0 bytes(44..50),
},
Punct {
ch: ',',
spacing: Alone,
span: #0 bytes(50..51),
},
Ident {
ident: "owner",
span: #0 bytes(56..61),
},
Punct {
ch: '=',
spacing: Alone,
span: #0 bytes(62..63),
},
Literal {
kind: Str,
symbol: "Canary M Burns",
suffix: None,
span: #0 bytes(64..80),
},
]
```