Rust: Suggest removal of stray `;` after `struct` definition

[estebank]

For the given code

struct Struct {
    a: usize,
};

the output is only

error: expected item, found `;`
  --> file.rs:15:2
   |
15 | };
   |  ^

where it should suggest removing the semicolon (as a suggestion so the RLS does the right thing)

error: expected item, found `;`
  --> file.rs:15:2
   |
15 | };
   |  ^ consider removing this semicolon

This is an edge situation, but I feel it is a common enough typo I've made and that is very likely to happen to newcomers.

[raventid]

I'll take this one :)

[est31]

Newcomers from C++ are likely to hit this error.

[colinmarsh19]

@jjolly @raventid I think I almost have a working solution to this. Will make a pull request when I compile in test.

[colinmarsh19]

This can be closed due to #46312 and #46258, I believe.

[kennytm]

Closing as fixed in #46258. Thanks for contribution!