RFR: 8267191: Avoid repeated SystemDictionaryShared::should_be_excluded calls [v3]

[Ioi Lam]

> `SystemDictionaryShared::should_be_excluded` is called during CDS dump time to see if a class should be excluded from the archive. This function calls itself to check super types. As a result, some classes many be checked more than once.
> 
> The repeated calls slows down dumping. Also, If a class is excluded, we will see multiple warning messages like this, which is too verbose and confusing.
> 
> 
> Skipping org/eclipse/osgi/util/NLS: Signed JAR
> Skipping org/eclipse/osgi/util/NLS: Signed JAR
> Skipping org/eclipse/osgi/util/NLS: Signed JAR
> 
> 
> BTW, to make the code a little easier to read, I also changed
> 
> 
>  warn_excluded(k, "Failed verification");
>  return true;
> 
> 
> to
> 
> 
> return  warn_excluded(k, "Failed verification");

Ioi Lam has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:

 - Merge branch 'master' into 8267191-avoid-repeated-should_be_excluded
 - @dholmes-ora comments
 - fixed merge
 - Merge branch 'master' of https://github.com/openjdk/jdk into 8267191-avoid-repeated-should_be_excluded
 - 8267191: Avoid repeated SystemDictionaryShared::should_be_excluded calls

-------------

Changes: https://git.openjdk.java.net/jdk/pull/4070/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4070&range=02
  Stats: 77 lines in 2 files changed: 28 ins; 22 del; 27 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4070.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4070/head:pull/4070

PR: https://git.openjdk.java.net/jdk/pull/4070