RFR: 8254090: Collectors.toUnmodifiableList exposes shared secret [v3]

[Stuart Marks]

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

Stuart Marks has updated the pull request incrementally with two additional commits since the last revision:

 - Update test/jdk/java/util/stream/test/org/openjdk/tests/java/util/stream/CollectorToUnmodListTest.java
   
   Fix copyright years.
   
   Co-authored-by: Claes Redestad <claes.redestad at gmail.com>
 - remove moar redundant casts

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/569/files
  - new: https://git.openjdk.java.net/jdk/pull/569/files/4c02f271..64079da9

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=569&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=569&range=01-02

  Stats: 5 lines in 2 files changed: 0 ins; 0 del; 5 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