Extra backslashes when generating a trait method

[JustinHuPrime]

rust-analyzer version: 0.3.1850-standalone

rustc version: rustc 1.75.0 (82e1608df 2023-12-21)

relevant settings: default settings

This is a regression from 0.3.1850 and 0.3.1839

When in 0.3.1850 (newer), asking RA to implement the missing members for a trait generates extra backslashes:

struct SomeStruct {
    field: i32,
}
impl Display for SomeStruct {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result \{
        todo!()
    \}
}

When in 0.3.1839 (older), asking RA to implement the same missing member generates the expected code without the extra backslashes:

struct SomeStruct {
    field: i32,
}
impl Display for SomeStruct {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        todo!()
    }
}

[l1nxy]

fixed in #16618

[flodiebold]

Duplicate of #16607