RFR: 7903780: NPE in new code for LIBRARY.properties

[Iris Clark]

On Tue, 23 Jul 2024 19:01:05 GMT, Jonathan Gibbons <jjg at openjdk.org> wrote:

> As well as the NPE, the following additional minor issues were fixed:
> 
> `--source` is a recent addition for `javac` options; older versions of `javac` still require `-source N`
> 
> `--enable-preview` is required at runtime if any library uses preview features.
> For now, I just moved `usesLibraryCompiledWithPreviewEnabled` from `CompileAction` up into `Action`, so that it can be used from `MainAction`. We might want to consider merging the merging into `RegressionScript.enablePreview`, but that can be done when we clean up the use of `LIBRARY.properties`, caching the results in `LibLocn`.
> 
> We should also investigate the difference between `libLocn == null` and `libLocn.isTest()` 
> 
> After this, all self-tests pass, including the recently new tests for `LIBRARY.properties`.

Thanks for fixing!

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Marked as reviewed by iris (Reviewer).

PR Review: https://git.openjdk.org/jtreg/pull/213#pullrequestreview-2195047789