Clarify return type of `String::from_utf16_lossy`.
Clarify return type of `String::from_utf16_lossy`.

Fixes https://github.com/rust-lang/rust/issues/32874

graydon/rust,aidancully/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust