[jdk11u-dev] RFR: 8216318: The usage of Disposer in the java.awt.Robot can be deleted

[Martin Doerr]

Clean backport of JDK-8216318.

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Commit messages:
 - Backport 293f77f18f96fec80d9dd5cc082d045b5dd0b813

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/365/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=365&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8216318
  Stats: 194 lines in 7 files changed: 6 ins; 161 del; 27 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/365.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/365/head:pull/365

PR: https://git.openjdk.java.net/jdk11u-dev/pull/365