RFR: 8307804: Reorganize ArrayJuggle test cases [v3]

[Leo Korinth]

> Move all ArrayJuggle test cases to the same directory: test/hotspot/jtreg/vmTestbase/gc/ArrayJuggle
> 
> Rename Juggle01 to Juggle3 (so it will not be confused with Juggle1)
> 
> Remove all directories and files used to launch the tests, instead use multiple  `@test id=xx` "annotations" in the four kept test files.
> 
> Create a new test file Juggle3Quick.java that will act as a quick group of tests. Unfortunately `#id` selectors can not be used in test groups so this is a workaround. See: https://bugs.openjdk.org/browse/CODETOOLS-7903467

Leo Korinth has updated the pull request incrementally with one additional commit since the last revision:

  remove comments, add descriptive ids, remove bad README

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13929/files
  - new: https://git.openjdk.org/jdk/pull/13929/files/7bda00db..5f9ab708

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13929&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13929&range=01-02

  Stats: 135 lines in 3 files changed: 0 ins; 101 del; 34 mod
  Patch: https://git.openjdk.org/jdk/pull/13929.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13929/head:pull/13929

PR: https://git.openjdk.org/jdk/pull/13929