[lworld] RFR: 8374025: [lworld] valhalla/valuetypes/SubstitutabilityTest.java fails due to argument clashes [v2]

[Paul Hübner]

> Hi all,
> 
> Currently, the non-CDS test of `valhalla/valuetypes/SubstitutabilityTest.java` is disabled. This is because it uses `-Xshare:off` which is fundamentally incompatible with some AOT flags that the test is run with.
> 
> In this fix, we introduce a new `@requires` property which denotes if the AOT code cache has been given as a command-line argument. If that is the case, we skip the test. For context, from the failure:
>> Option AOTCache cannot be used at the same time with -Xshare:on, -Xshare:auto, -Xshare:off, -Xshare:dump, DumpLoadedClassList, SharedClassListFile, or SharedArchiveFile
> 
> An alternative considered was to use `@requires vm.flagless`. However, there are many configurations, such as different GCs, that we would lose out on. Substitutability plays quite a central concept with value classes, therefore, a new property is perhaps the more suitable approach.
> 
> Testing: the Oracle tiers in which we observed failures, and a smoke-test tier 1 on Linux (x64, AArch64), macOS (x64, AArch64), Windows (x64).

Paul Hübner has updated the pull request incrementally with two additional commits since the last revision:

 - Merge and don't share.
 - Revert "Restrain SubstitutabilityTest with -Xshare:off."
   
   This reverts commit 0fc69eb72574f32b802fdf0a06ecc46fb0fcf3e2.

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1995/files
  - new: https://git.openjdk.org/valhalla/pull/1995/files/0fc69eb7..ab8ab1be

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1995&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1995&range=00-01

  Stats: 28 lines in 4 files changed: 1 ins; 23 del; 4 mod
  Patch: https://git.openjdk.org/valhalla/pull/1995.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1995/head:pull/1995

PR: https://git.openjdk.org/valhalla/pull/1995