RFR: 8302513: remove sun.awt.util.IdentityLinkedList

[Stuart Marks]

IdentityLinkedList is used in only one place, so it's fairly simple to replace it with IdentityArrayList.

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Commit messages:
 - Replace IdentityLinkedList with IdentityArrayList.

Changes: https://git.openjdk.org/jdk/pull/12567/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12567&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8302513
  Stats: 882 lines in 2 files changed: 0 ins; 881 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/12567.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12567/head:pull/12567

PR: https://git.openjdk.org/jdk/pull/12567