Documentation of the From<String> impl for OsString misleading

[smarnach]

The documentation of From<String> for OsString reads

Converts a String into a OsString.

The conversion copies the data, and includes an allocation on the heap.

The implementation is platform-specific, but from a quick glance none of the implementations I looked at does seem to actually copy the data.

The documentation of From<String> for PatBbuf reads

Converts a String into a PathBuf

This conversion does not allocate or copy memory.

It is implemented using OsString::from::<String>:

fn from(s: String) -> PathBuf {
    PathBuf::from(OsString::from(s))
}

So clearly something is off here. Even when all current implementations of the String to OsString conversion avoid copying, the documentation does not necessarily need to commit to this property, but neither should it state that the implementation allocates and copies if it actually doesn't.

[ChrisDenton]

This was fixed by #83700.