build-parameters: add "target Java release" parameter, split toolchains for the build and test execution

[vlsi]

Deliverables

• "Target Java release" seems to be hard-coded for now, and it is worth moving to a build parameter. It should propagate to JavaCompile.options...release and KotlinJvmCompile...Xjdk-release, and jvmTarget

• JUnit should probably be built with the latest Java, and there should be a possibility to test it with a different version. Thus two toolchain properties are needed: one for build, another one for test.

See:

• https://github.com/junit-team/junit5/blob/934d05e602892b438c390690f0e16a483bd11fbb/gradle/plugins/build-parameters/build.gradle.kts#L15-L21

[AbhishekHerbertSamuel]

Hi @marcphilipp , I’d like to work on this issue. Please let me know if there’s any ongoing work or specific direction you'd like me to follow.

[marcphilipp]

@AbhishekHerbertSamuel I don't have time to provide proper guidance for this issue at the moment. If you want, feel free to take a look at our conventions plugins (in particular java-library-conventions, kotlin-library-conventions, and java-toolchain-conventions) as well as the build parameters definitions that are linked in the issue description.

[AbhishekHerbertSamuel]

@marcphilipp No issues, will take a look at the plugins and definitions.