RFR: 8523: Update version to 9.1.2

[Suchita Chaturvedi]

This PR is to Update version to 9.1.2

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

Commit messages:
 - 8523: Update version to 9.1.2

Changes: https://git.openjdk.org/jmc/pull/701/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=701&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8523
  Stats: 224 lines in 152 files changed: 0 ins; 0 del; 224 mod
  Patch: https://git.openjdk.org/jmc/pull/701.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/701/head:pull/701

PR: https://git.openjdk.org/jmc/pull/701