RFR: 8356977: UTF-8 cleanups

[Magnus Ihse Bursie]

I found a few other places in the code that can be cleaned up after the conversion to UTF-8.

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Commit messages:
 - Replace uncessary unicode characters with ASCII in instructions, and fix typo
 - Seems like typos in the comments
 - Fix unicode sequences in comments (previously missed)

Changes: https://git.openjdk.org/jdk/pull/25228/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25228&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8356977
  Stats: 21 lines in 16 files changed: 0 ins; 0 del; 21 mod
  Patch: https://git.openjdk.org/jdk/pull/25228.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25228/head:pull/25228

PR: https://git.openjdk.org/jdk/pull/25228