Comments removed before unnecessary semicolon

[HactarCE]

Describe the bug

When rustfmt deletes an unnecessary semicolon, it also deletes comments immediately before that semicolon.

Obviously this isn't a common scenario, but rustfmt should never delete comments.

To Reproduce

Try it on the Rust Playground

Expected behavior

The extraneous semicolon should be deleted but the comment should remain.

Meta

• rustfmt version: 1.4.20-nightly (2020-08-09 48f6c32)
• From where did you install rustfmt?: Rust Playground (also rustup)
• How do you run rustfmt: Rust Playground (also cargo fmt)

[ayazhafiz]

Fixed on master since #4180

[calebcartwright]

Thanks for confirming @ayazhafiz! Closing accordingly