Fix overrides of removed in gradle 6.0 AbstractCompile.compile

https://github.com/gradle/gradle/commit/5e7476de957792b6d2f164968b4023539a0385f2

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/KotlinNativeTasks.kt

@@ -239,7 +239,7 @@ abstract class AbstractKotlinNativeCompile<T : KotlinCommonToolOptions> : Abstra
         buildCompilerArgs() + buildCommonArgs() + buildSourceArgs()
 
     @TaskAction
-    override fun compile() {
+    open fun compile() {
         val output = outputFile.get()
         output.parentFile.mkdirs()
         KonanCompilerRunner(project).run(buildArgs())

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/KotlinJsDce.kt

@@ -63,8 +63,6 @@ open class KotlinJsDce : AbstractKotlinCompileTool<K2JSDceArguments>(), KotlinJs
 
     override fun findKotlinCompilerClasspath(project: Project): List<File> = findKotlinJsDceClasspath(project)
 
-    override fun compile() {}
-
     override fun keep(vararg fqn: String) {
         keep += fqn
     }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/Tasks.kt

@@ -259,10 +259,6 @@ abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractKo
     internal open fun compilerRunner(): GradleCompilerRunner =
         GradleCompilerRunner(this)
 
-    override fun compile() {
-        assert(false, { "unexpected call to compile()" })
-    }
-
     @TaskAction
     fun execute(inputs: IncrementalTaskInputs) {
         // If task throws exception, but its outputs are changed during execution,