RFR: 8290041: ModuleDescriptor.hashCode is inconsistent

Sat Aug 6 08:16:47 UTC 2022

Can I please get a review of this change which proposes to fix https://bugs.openjdk.org/browse/JDK-8290041? 

As noted by the reporter, the current implementation is buggy since the calculation can result in a different value of the hashcode depending on the order of iteration of the `Modifier`s. The commit in this PR changes that computation to produce consistent result irrespective of the order in which the `Modifier`s (enum) is iterated upon.

A new test has been added which reproduces the issue and verifies the fix.

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Commit messages:
 - 8290041: ModuleDescriptor.hashCode is inconsistent

Changes: https://git.openjdk.org/jdk/pull/9790/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9790&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8290041
  Stats: 47 lines in 2 files changed: 41 ins; 3 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/9790.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9790/head:pull/9790

PR: https://git.openjdk.org/jdk/pull/9790