RFR: 8267832: SimpleVisitors and Scanners in jdk.compiler should use @implSpec [v3]

[Jan Lahoda]

> As noted in:
> https://bugs.openjdk.java.net/browse/JDK-8265981?focusedCommentId=14423316&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14423316
> 
> Methods in various utility visitor classes in jdk.compiler should use @implSpec to specify the implementation behavior. This patch tries to add the @implSpec tag to methods which already contain a text specifying the implementation, and adds new javadoc to the handful of methods that are missing it so far.
> 
> The CSR is started for review here:
> https://bugs.openjdk.java.net/browse/JDK-8267838

Jan Lahoda has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 15 commits:

 - Merging master into JDK-8267833
 - Reordering @implSpec and example as suggested.
 - 8267832: SimpleVisitors and Scanners in jdk.compiler should use @implSpec
 - Post-merge fix - need to include jdk.internal.javac in the list of packages used by jdk.compiler again, as we now (again) have a preview feature in javac.
 - Correcting LineNumberTable for rule switches.
 - Merging master into JDK-8262891
 - Fixing various error-related bugs.
 - Avoiding fall-through from the total case to a synthetic default but changing total patterns to default.
 - Reflecting recent spec changes.
 - Reflecting review comments.
 - ... and 5 more: https://git.openjdk.java.net/jdk/compare/908aca29...7cea033a

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

Changes: https://git.openjdk.java.net/jdk/pull/4223/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4223&range=02
  Stats: 749 lines in 4 files changed: 529 ins; 28 del; 192 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4223.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4223/head:pull/4223

PR: https://git.openjdk.java.net/jdk/pull/4223