RFR: 8289: Remove security manager related code [v2]

[Marcus Hirt]

> Cherry picked my changes into a new branch.

Marcus Hirt has updated the pull request incrementally with one additional commit since the last revision:

  Fixing unused imports

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

Changes:
  - all: https://git.openjdk.org/jmc/pull/642/files
  - new: https://git.openjdk.org/jmc/pull/642/files/0d4eed70..b299ee38

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jmc&pr=642&range=01
 - incr: https://webrevs.openjdk.org/?repo=jmc&pr=642&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jmc/pull/642.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/642/head:pull/642

PR: https://git.openjdk.org/jmc/pull/642