RFR: 8341904: Search tag in inherited doc comment creates additional index item [v2]

[Hannes Wallnöfer]

> Please review a change to avoid generation of index items for comments inherited from overridden methods. This affects `{@index}`, `{@systemProperty}`, and `@spec` tags in both implicitly and explicitly doc comments. 
> 
> The change adds two additional means for avoiding generation of index items which partially overlap:
> 
>  - Adding the `inheritDoc` tag to the current `TagletWriter.Context` when rendering an inherited doc comment
>  - Comparing the element's type element with the type element currently being documented
> 
> The second check is necessary for implicitly inherited doc comments (e.g. overriding a method without doc comment), while usage of `{@inheritDoc}` tag is detected by checks. I still decided to add the `inheritDoc` tag constant to `TagletWriter.Context` since it is explicit, uses a mechanism that was created for the purpose, and might be useful in other places. 
> 
> There was a test case for the previous (buggy) behaviour to add a search tag index item using the overridden method signature as label. I changed the expected behaviour and added another method to cover usage of the `{@systemProperty}` tag in combination with `{@inheritDoc}`.

Hannes Wallnöfer has updated the pull request incrementally with one additional commit since the last revision:

  Address review feedback

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/21765/files
  - new: https://git.openjdk.org/jdk/pull/21765/files/da445e10..967f2093

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21765&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21765&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/21765.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21765/head:pull/21765

PR: https://git.openjdk.org/jdk/pull/21765