[jdk11u-dev] RFR: 8297437: javadoc cannot link to old docs (with old style anchors) [v4]

[Roman Marchenko]

> Backporting JDK-8297437 to 11u for parity, because there are still scenarios for 11u when docs being generated are linked to external old-style anchors docs.
> 
> No tier1 regressions.
> The tests from "test/langtools/jdk/javadoc" are passed, except jdk/javadoc/doclet/testIOException/TestIOException.java - it fails on master as well.
> 
> Refactoring was made in Links.java to avoid duplicating function code.

Roman Marchenko has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - Merge branch 'openjdk:master' into backport-15a14884013a975707008f648b8e4864e16006ed
 - Merge branch 'openjdk:master' into backport-15a14884013a975707008f648b8e4864e16006ed
 - Merge branch 'openjdk:master' into backport-15a14884013a975707008f648b8e4864e16006ed
 - Tests fixing
 - Refactoring
 - Backport 15a14884013a975707008f648b8e4864e16006ed

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

Changes:
  - all: https://git.openjdk.org/jdk11u-dev/pull/1794/files
  - new: https://git.openjdk.org/jdk11u-dev/pull/1794/files/15aaa76f..10db7e1d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1794&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1794&range=02-03

  Stats: 20 lines in 5 files changed: 7 ins; 9 del; 4 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1794.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/1794/head:pull/1794

PR: https://git.openjdk.org/jdk11u-dev/pull/1794