RFR: 8195744: Avoid calling ClassLoader.checkPackageAccess if security manager is not installed [v2]

[Coleen Phillimore]

> This change does not call up to Java for checkPackageAccess if the security manager is NULL, but still saves the protection domain in the pd_set for that dictionary entry.  If the option -Djava.security.manager=disallow is set, that means that there will never be a security manager and the JVM code can avoid saving the protection domains completely. 
> See the two functions java_lang_System::has_security_manager() and java_lang_System::allow_security_manager() for details.
> Also deleted ProtectionDomainVerification because there's no use for this option.
> 
> Tested with tier1 hotspot, jdk and langtools.
> and tier2-6.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Add comment and read NEVER field from System

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2410/files
  - new: https://git.openjdk.java.net/jdk/pull/2410/files/19ddd066..296d0adb

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2410&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2410&range=00-01

  Stats: 25 lines in 3 files changed: 17 ins; 7 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2410.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2410/head:pull/2410

PR: https://git.openjdk.java.net/jdk/pull/2410