[jdk11u-dev] RFR: 8211171: move JarUtils to top-level testlibrary

[Goetz Lindenmaier]

I downport this for parity with 11.0.13-oracle.

I want to bring this to 11 as there is a testbug fix (8180568) that 
uses the new JarUtils. Unfortunately, there are two (three)
versions of it, and the new one lacks some changes to work for 
that testbug fix.
So I think it is better to bring down this change and use only
one JarUtils that is updated properly in case of further problems.
There is already a fix pending:  8240235

One test already uses the new version.
In addition, I had to adapt javax/naming/spi/FactoryCacheTest.java
which was using the old JarUtils.

To the JarUtils file itself, some of the changes of 8211171 were 
already in that file.

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Commit messages:
 - Backport ab8c7f710c8a4c46fc2f2a295c921054a30a7d2f

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/441/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=441&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8211171
  Stats: 552 lines in 42 files changed: 144 ins; 350 del; 58 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/441.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/441/head:pull/441

PR: https://git.openjdk.java.net/jdk11u-dev/pull/441