RFR: 8258852: Arrays.asList() for single item could be replaced with List.of() [v2]

[Xue-Lei Andrew Fan]

> If there is only one item, the call to Arrays.asList() could be replaced with List.of() for less memory occupation.  This update also includes some other code cleanup, like redundant variables in the related files.
> 
> Code cleanup only, no new regression test.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8258852

Xue-Lei Andrew Fan has updated the pull request incrementally with one additional commit since the last revision:

  Replace Collections.singletonList() with List.of()

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1872/files
  - new: https://git.openjdk.java.net/jdk/pull/1872/files/6fefd872..343cc014

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1872&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1872&range=00-01

  Stats: 8 lines in 3 files changed: 0 ins; 1 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1872.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1872/head:pull/1872

PR: https://git.openjdk.java.net/jdk/pull/1872