RFR: Some AOTCodeCache cleanup after merge from mainline

[Ashutosh Mehra]

Additional cleanup following Vladimir's merge of mainline to premain.

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Commit messages:
 - Some AOTCodeCache cleanup after merge from mainline

Changes: https://git.openjdk.org/leyden/pull/66/files
  Webrev: https://webrevs.openjdk.org/?repo=leyden&pr=66&range=00
  Stats: 671 lines in 5 files changed: 11 ins; 652 del; 8 mod
  Patch: https://git.openjdk.org/leyden/pull/66.diff
  Fetch: git fetch https://git.openjdk.org/leyden.git pull/66/head:pull/66

PR: https://git.openjdk.org/leyden/pull/66