RFR: JDK-8263043: Add test to verify order of tag output [v3]

[Jonathan Gibbons]

> Please review a new test to verify that the output of block tags is generated in the expected order.
> 
> The code in the standard doclet to generate the output is the same for all use sites (modules, packages, class, members) and so just the richest site is tested.
> 
> The test checks that tags appear in the expected order by default, but can be reordered in a couple of different ways.

Jonathan Gibbons has updated the pull request incrementally with one additional commit since the last revision:

  Update TestTagOrder.java
  
  Fix whitespace

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2835/files
  - new: https://git.openjdk.java.net/jdk/pull/2835/files/395cca1b..8ad33ab7

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2835&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2835&range=01-02

  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2835.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2835/head:pull/2835

PR: https://git.openjdk.java.net/jdk/pull/2835