RFR: 8346661: Add a register print helper method and unify register printing

[Matthias Baesken]

For printing registers we can add a little helper method to shorten the coding. Also some of the register printing code can use loops.

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Commit messages:
 - JDK-8346661

Changes: https://git.openjdk.org/jdk/pull/22894/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22894&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8346661
  Stats: 191 lines in 10 files changed: 29 ins; 85 del; 77 mod
  Patch: https://git.openjdk.org/jdk/pull/22894.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22894/head:pull/22894

PR: https://git.openjdk.org/jdk/pull/22894