Apply the `kotlin-dsl` plugin to `buildSrc`
The `kotlin-dsl` plugin
- applies the `org.jetbrains.kotlin.jvm` plugin,
- configures an embedded repository that contains all Kotlin libraries embedded into Gradle,
- and pins them to the embedded Kotlin version,
- it also adds compile only dependencies on `kotlin-stdlib` and `kotlin-reflect`,
- and adds the `gradleKotlinDsl()` dependency to the `compileOnly` and `testRuntimeOnly` configurations,
- and configures the Kotlin DSL compiler plugins
This commit also includes changes to:
- gradle/compile.gradle
- gradle/strictCompile.gradle
Those scripts assumed all `AbstractCompile` tasks to have an `options`
property. This is not the case. Java, Groovy and Scala compilation tasks
do, but the KotlinCompile tasks now present in `buildSrc` don't.
gradle/compile.gradle now target only the tasks we are interested by, that is Java and Groovy compilation tasks.
There are no scala compilation tasks in the Gradle build itself.
Signed-off-by: Paul Merlin <paul@gradle.com>