RFR: 8344077: Remove security manager dependency in java.io [v3]

[Brian Burkhalter]

> Expunge the use of the `SecurityManager`, `AccessController`, and the like from the `java.io` package.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8344446: Revert spurious inclusion of SCTP changes

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22219/files
  - new: https://git.openjdk.org/jdk/pull/22219/files/c7ba3354..a15574a3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22219&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22219&range=01-02

  Stats: 59 lines in 3 files changed: 54 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/22219.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22219/head:pull/22219

PR: https://git.openjdk.org/jdk/pull/22219