RFR: 8332161: Test restoring echo in the Console implementation (java.base) [v8]

[Naoto Sato]

> This test intends to verify the behavior of JdkConsole for the java.base module, wrt restoring the echo. The test assumes the internal methods that sets/gets the echo status of the platform.

Naoto Sato has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 26 commits:

 - Corrected comments
 - Merge branch 'master' into JDK-8332161-restoreEcho-Test
 - Check restored echo with stty -a
 - incorporated the same fix from 8332922
 - Merge branch 'master' into JDK-8332161-restoreEcho-Test
 - Merge branch 'master' into JDK-8332161-restoreEcho-Test
 - Merge branch 'JDK-8332084-restoreEcho-readLock' into JDK-8332161-restoreEcho-Test
 - Added comment for restoreEchoLock
 - fixing typo
 - Merge branch 'JDK-8332084-restoreEcho-readLock' into JDK-8332161-restoreEcho-Test
 - ... and 16 more: https://git.openjdk.org/jdk/compare/9686e804...1c0ab8eb

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Changes: https://git.openjdk.org/jdk/pull/19315/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19315&range=07
  Stats: 158 lines in 2 files changed: 158 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/19315.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19315/head:pull/19315

PR: https://git.openjdk.org/jdk/pull/19315