Expand box and IR diagnostic compiler-tests to support multiple platforms

[ZacSweers]

This would allow moving integration tests over to this

CC @bnorm

[ZacSweers]

So to do this metro would need to copy some common base tests from the kotlin repo, as it seems the test framework currently only ships JVM base classes

[ZacSweers]

This test infra ships in Kotlin 2.3.0: JetBrains/kotlin@264f4b4

Kotlin/compiler-plugin-template#27