Avoid the accidental removal of comments inside expressions by dx fmt (#4410)

* Avoid the accidental removal of comments inside expressions by dx fmt

* Rewrite the logic to pass failed tests

* Removed unnecessary call to write_inline_comments

* add failing test case

* alter parsing a bit to handle more test cases

* almost there...

* fix

* use threadlocal

---------

Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

Cargo.lock

@@ -5022,6 +5022,7 @@ dependencies = [
  "prettyplease",
  "proc-macro2",
  "quote",
+ "regex",
  "serde",
  "syn 2.0.104",
 ]