RFR: 8376274: JSpec preview support and output enhancement [v2]

[Chen Liang]

> We can enhance the `@jls` and `@jvms` tags in-place to support preview JLS/JVMS, such as in this PR:
> 
> 
> @jls primitive-types-in-patterns-instanceof-switch-5.7.1 Exact Testing Conversions
> 
> 
> Taglet now parses "primitive-types-in-patterns-instanceof-switch-" preview and links to `primitive-types-in-patterns-instanceof-switch-jls.html` where the 5.7.1 anchor exists.
> 
> As a side effect, I adjusted the output to remove the preview prefix, and discovered we can embellish the output more, in particular, including a section sign for inline tags and including a trailing dot for block tags.
> 
> I need this feature in project Valhalla, where there are JLS and JVMS for value-objects and strict-fields that we need to link to. Please help review!

Chen Liang has updated the pull request incrementally with one additional commit since the last revision:

  Remove redundant dot

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/29402/files
  - new: https://git.openjdk.org/jdk/pull/29402/files/f76fa06c..74af3243

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29402&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29402&range=00-01

  Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/29402.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29402/head:pull/29402

PR: https://git.openjdk.org/jdk/pull/29402