RFR: 8341625: Improve ZipFile validation of the END header [v3]

[Eirik Bjørsnøs]

> Please review this PR which adds validation of the 'total entries' value when fetched from the 'ZIP64 End of Central Directory' header.
> 
> We should reject this value under the following conditions:
> 
> 1. It is too large to fit within the specified CEN size (considering each CEN header encodes as at least 46 bytes each)
> 2. It is too large to create the `int[] entries` array safely (max value is `ArraysSupport.SOFT_MAX_ARRAY_LENGTH / 3`)
> 
> I claim that condition 2 here is already implicitly validated by the current maximum CEN size validation. (A CEN encoding such a large number of entries would exceed the maximum CEN size a lot and would already be rejected)
> 
> This change aims to protect the integrity of the implementation against specially crafted ZIP files. No sane ZIP tool will produce such files. 
> 
> Testing:
> 
> This PR adds a test `EndOfCenValidation.shouldRejectBadTotalEntries` which exercises the first condition above.
> 
> ZIP tests run locally. GHA results pending.

Eirik Bjørsnøs has updated the pull request incrementally with two additional commits since the last revision:

 - Reject "negative" 'total entries' values
 - Convert EndOfCenValidation to JUnit 5

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/21384/files
  - new: https://git.openjdk.org/jdk/pull/21384/files/ccfa56e4..0f0801c4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21384&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21384&range=01-02

  Stats: 29 lines in 2 files changed: 9 ins; 0 del; 20 mod
  Patch: https://git.openjdk.org/jdk/pull/21384.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21384/head:pull/21384

PR: https://git.openjdk.org/jdk/pull/21384