RFR: JDK-8261079: Fix support for @hidden in classes and interfaces [v3]

[Jonathan Gibbons]

On 2/11/21 4:10 AM, Hannes Wallnöfer wrote:
>   - JDK-8261079: Updates to review comments
>      - Use separate unchecked/uncached code path when checking for @hidden tag on non-incuded elements


I think you'll find that if you dig deep enough, it is not so much 
"uncached" as "less cached"!

The comments read from files are cached deep down in `jdk.compiler`  
(JCTrees:533, DocCommentTable) ... the additional level of caching in 
javadoc is to support caching of synthetic comments, such as for the 
mandated methods on enum and record classes.

-- Jon