RFR: JDK-8286617: Improve parameter names in javax.lang.model utility visitors

[Joe Darcy]

Fix inconsistencies in parameter naming; will update copyrights years if needed before a push.

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Commit messages:
 - JDK-8286617: Improve parameter names in javax.lang.model utility visitors

Changes: https://git.openjdk.java.net/jdk/pull/8671/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8671&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8286617
  Stats: 6 lines in 3 files changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8671.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8671/head:pull/8671

PR: https://git.openjdk.java.net/jdk/pull/8671