RFR: 8267347: CDS record_linking_constraint asserts with unregistered class

[Ioi Lam]

In CDS terms, "Unregistered classes" are the archived classes that should be loaded by custom class loaders during runtime. Archiving of class loader constraints ([JDK-8178349](https://bugs.openjdk.java.net/browse/JDK-8178349)) should be disabled for such classes.

During CDS dump time (-Xshare:dump), unregistered classes are loaded by the boot loader (see also [JDK-8261941](https://bugs.openjdk.java.net/browse/JDK-8261941)). `SystemDictionaryShared::record_linking_constraint` doesn't properly recognize such classes, leading to the assert.

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Commit messages:
 - fixed windows testing
 - 8267347: CDS record_linking_constraint asserts with unregistered class

Changes: https://git.openjdk.java.net/jdk/pull/4147/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4147&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8267347
  Stats: 161 lines in 5 files changed: 138 ins; 4 del; 19 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4147.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4147/head:pull/4147

PR: https://git.openjdk.java.net/jdk/pull/4147