[jdk21u-dev] RFR: 8342988: GHA: Build JTReg in single step

[Sergey Bylokhov]

On Wed, 18 Dec 2024 17:21:06 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Makes sure GHA is more reliable: we do not risk failures when building jtreg multiple times, and it also allows us to compile it once on x86, without bothering with different arch JDKs.
> 
> The original PR does not apply cleanly, because Alpine support added by [JDK-8282944](https://bugs.openjdk.org/browse/JDK-8282944) is not in JDK 21. I have resolved the block by hand.
> 
> Additional testing:
>  - [x] GHA

Marked as reviewed by serb (Reviewer).

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

PR Review: https://git.openjdk.org/jdk21u-dev/pull/1269#pullrequestreview-2539706836