RFR: 8343958: Remove security manager impl in java.lang.Process and java.lang.Runtime.exec [v5]

[Roger Riggs]

> Refactor removing the dependencies on SecurityManager, doPrivileged, and AccessController.

Roger Riggs has updated the pull request incrementally with two additional commits since the last revision:

 - Merge branch '8343958-process-sm-cleanup' of https://github.com/RogerRiggs/jdk into 8343958-process-sm-cleanup
 - Revert unnecessary copyright change in ProcessEnvironment.java.
   Fix code style in ProcessImpl
   Drop unneeded suppress warnings.
   Remove obsolete @throws SecurityExceptions
   Correct compilation errors in Windows ProcessImpl

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22024/files
  - new: https://git.openjdk.org/jdk/pull/22024/files/accc6df3..16d11e1c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22024&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22024&range=03-04

  Stats: 3 lines in 1 file changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22024.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22024/head:pull/22024

PR: https://git.openjdk.org/jdk/pull/22024