Adjust the specification of the `SequencedMap` sequenced-view methods, and adjust implementations to match.
------------- Commit messages: - Minor wording adjustment. - 8307840: SequencedMap view method specification and implementation adjustments Changes: https://git.openjdk.org/jdk/pull/14267/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14267&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8307840 Stats: 113 lines in 3 files changed: 64 ins; 3 del; 46 mod Patch: https://git.openjdk.org/jdk/pull/14267.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/14267/head:pull/14267 PR: https://git.openjdk.org/jdk/pull/14267
