Pass `javacArguments` to Kapt

[GavinRay97]

Passes javacArguments option through to Kapt. This is required for code which uses things like --enable-preview or --add-opens

(Closes: https://github.com/tschuchortdev/kotlin-compile-testing/issues/385)

Kapt requires a Map<String, String> for it's javac arguments, so convert it from a List<String>

See the function working here:

• https://pl.kotl.in/JFrNpLMu9

val args = listOf(
    "-verbose",
    "-cp", "path/to/classes",
    "-J-Xmx512m",
    "-g:none",
    "-source", "1.8",
    "--add-opens", "java.base/java.util=ALL-UNNAMED"
)

val result = convertJavacArgumentsListToMap(args)
result.forEach { (key, value) -> println("Key: $key Value: $value") }

Key: -verbose Value: 
Key: -cp Value: path/to/classes
Key: -J-Xmx512m Value: 
Key: -g:none Value: 
Key: -source Value: 1.8
Key: --add-opens Value: java.base/java.util=ALL-UNNAMED
``` 

[tschuchortdev]

Thanks for your PR! Does this fix the issue you were having in #385, i.e. did you confirm that the options are actually passed to kapt correctly? It would be good to have at least one test to exercise this, but --enable-preview probably can't be used because it is not available in earlier JDK versions. Perhaps it is sufficient to search the logs for javac options passed to kapt.

[GavinRay97]

No problem =)

Does this fix the issue you were having in https://github.com/tschuchortdev/kotlin-compile-testing/issues/385, i.e. did you confirm that the options are actually passed to kapt correctly?

It does, the code runs without issue after this patch 👍

It would be good to have at least one test to exercise this, but --enable-preview probably can't be used because it is not available in earlier JDK versions.

I thought about adding a test but like you said, it would mean forcing the JDK to something like a minimum of JDK 17 or so for --enable-preview

Perhaps it is sufficient to search the logs for javac options passed to kapt.

Good idea -- this sounds reasonable to me 👍