RFR: 8254090: Collectors.toUnmodifiableList exposes shared secret [v2]

[Stuart Marks]

> Add check for ArrayList.class before passing it to the shared secret.

Stuart Marks 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 four additional commits since
the last revision:

 - Merge branch 'master' into JDK-8254090-Collectors-toUnmodifiableList-SharedSecret
 - remove unnecessary cast and warnings suppression
 - update copyright on test
 - 8254090: Collectors.toUnmodifiableList exposes shared secret

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/569/files
  - new: https://git.openjdk.java.net/jdk/pull/569/files/b27a0ba1..4c02f271

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=569&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=569&range=00-01

  Stats: 2249 lines in 90 files changed: 1365 ins; 633 del; 251 mod
  Patch: https://git.openjdk.java.net/jdk/pull/569.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/569/head:pull/569

PR: https://git.openjdk.java.net/jdk/pull/569