RFR: 8330179: Clean up non-standard use of /** comments in `jdk.compiler`

[Joe Darcy]

On Fri, 12 Apr 2024 21:45:18 GMT, Jonathan Gibbons <jjg at openjdk.org> wrote:

> Please review a fix to preempt warnings that would otherwise be introduced by [JDK-8303689](https://bugs.openjdk.org/browse/JDK-8303689), which introduces a new `javac` lint warning to detect documentation comments in unusual places.
> 
> The majority of the warnings are caused by "box comments" beginning with `/*****`. To minimize change and to address these, the second `*` is replaced by a space. An alternative solution might be to change the overall style of the box comment to use something like `/*---------`

Marked as reviewed by darcy (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/18767#pullrequestreview-2004597666