RFR: 8285470: Improve handling of @inheritDoc [v2]

[Pavel Rappo]

> The only taglet that along with its own tag needs to know the immediately enclosing tag is `InheritDocTaglet`:
> 
>     @return {@inheritDoc}
>     @throws NullPointerException {@inheritDoc}
>     @param p {@inheritDoc}
> 
> However, the immediately enclosing tag is unconditionally passed to all taglets. If we stop passing it and make `InheritDocTaglet` compute it instead, the code becomes cleaner.
> 
> While reviewing, particularly note these benefits of the proposed change:
> 
>  * taglet-handling code knows less about `@inheritDoc`, and
>  * `InheritDocTaglet` receives its own tag, not the tag that encloses it

Pavel Rappo has updated the pull request incrementally with one additional commit since the last revision:

  (fix) Fix a test failure
  
  Fixes a failure in jdk/javadoc/doclet/testInheritDocWithinInappropriateTag/TestInheritDocWithinInappropriateTag.java

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8361/files
  - new: https://git.openjdk.java.net/jdk/pull/8361/files/3a99bf95..4c6c196b

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8361&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8361&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 1 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8361.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8361/head:pull/8361

PR: https://git.openjdk.java.net/jdk/pull/8361