RFR: 8343981: Remove usage of security manager from Thread and related classes [v3]

[Alan Bateman]

> Removes the SecurityManager usage from Thread + friends.
> 
> In Thread, the getContextClassLoader method is no longer caller-sensitive method.
> 
> JavaLangAccess.newThreadWithAcc is removed and jdk.internal.access is no longer exported to java.naming. The usage of newThreadWithAcc is removed from com.sun.jndi.ldap.VersionHelper. There will be further work on the java.naming module to remove usage of SM, the change here is specific to the usage of ewThreadWithAcc.

Alan Bateman has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 226 commits:

 - Merge commit 'db85090553ab14a84c3ed0a2604dd56c5b6e6982' into JDK-8343981
 - Initial commit
 - Merge remote-tracking branch 'jdk-sandbox/jep486' into JDK-8338411
 - Merge branch 'master' into jep486
 - Move remaining JEP 486 failing tests into correct groups.
 - Move JEP 486 failing tests into hotspot_runtime group.
 - test/jdk/java/rmi/server/RMIClassLoader/spi/DefaultProperty.java failing
 - Merge branch 'master' into jep486
 - Merge branch 'master' into jep486
 - Merge remote-tracking branch 'jdk-sandbox/jep486' into JDK-8338411
 - ... and 216 more: https://git.openjdk.org/jdk/compare/db850905...4f320f92

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Changes: https://git.openjdk.org/jdk/pull/22035/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22035&range=02
  Stats: 283 lines in 11 files changed: 0 ins; 228 del; 55 mod
  Patch: https://git.openjdk.org/jdk/pull/22035.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22035/head:pull/22035

PR: https://git.openjdk.org/jdk/pull/22035