RFR: 8358543: Remove CommentChecker.java and DirDiff.java

[Erik Joelsson]

On Tue, 3 Jun 2025 20:11:27 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

> These two tools were moved to src/utils/src/build/tools/ during the build-infra project. It was not part of the build, but two standalone tools that nobody knew who created or who used them.
> 
> I think we can safely delete them now.

Marked as reviewed by erikj (Reviewer).

-------------

PR Review: https://git.openjdk.org/jdk/pull/25629#pullrequestreview-2896675165