RFR: JDK-8310571: Use inline @return tag on java.util.Objects [v2]

[Joe Darcy]

> Small cleanup, minor differences in the wording of portions of toString(Object, String), nonNull(Object), requireNonNullElse, and requireNonNullElseGet.

Joe Darcy has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Respond to review feedback.
 - Merge branch 'master' into JDK-8310571
 - Merge branch 'master' into JDK-8310571
 - JDK-8310571: Use inline @return tag on java.util.Objects

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/14608/files
  - new: https://git.openjdk.org/jdk/pull/14608/files/026b3caf..d97eb7ab

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14608&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14608&range=00-01

  Stats: 1039 lines in 88 files changed: 319 ins; 408 del; 312 mod
  Patch: https://git.openjdk.org/jdk/pull/14608.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14608/head:pull/14608

PR: https://git.openjdk.org/jdk/pull/14608