Change some reverse-ordered spliterators to use `Spliterators.spliterator(Collection, ORDERED)` instead of `Spliterators.spliteratorUnknownSize()`. This gives SIZED and ORDERED spliterators. More optimizations will be done later. I'm intending to backport this to JDK 21 so I want this to be minimal.
I've also included some adjustments to spliterator implementation comments to clear up a few points of confusion. (No spec changes.) ------------- Commit messages: - Update some Spliterator comments; change default views to use spliterator(Collection). Changes: https://git.openjdk.org/jdk/pull/14854/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14854&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8306785 Stats: 30 lines in 6 files changed: 18 ins; 4 del; 8 mod Patch: https://git.openjdk.org/jdk/pull/14854.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/14854/head:pull/14854 PR: https://git.openjdk.org/jdk/pull/14854
