RFR: 8344187: Remove SecurityManager and related calls from java.lang.instrument

[Kevin Walls]

Remove redundant SecurityManager, AccessController references
(following on from JDK-8338411: Implement JEP 486: Permanently Disable the Security Manager).

test/jdk/java/lang/instrument/ still passing.

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Commit messages:
 - update
 - 8344187: Remove SecurityManager and related calls from java.instrument

Changes: https://git.openjdk.org/jdk/pull/22106/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22106&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8344187
  Stats: 31 lines in 2 files changed: 0 ins; 25 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/22106.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22106/head:pull/22106

PR: https://git.openjdk.org/jdk/pull/22106