[K/N][build] Add artifacts depending on input in library task

Depending on noPack option compiler produces file or directory.
Artifact field that contains .klib file can't use @OutputDirectory
annotation. The same applies for @OutputFile with directory.
To workaround make an artifact field internal and use two optional
fields that return either file or directory depending on noPack option.

kotlin-native/runtime/build.gradle.kts

@@ -439,7 +439,6 @@ konanArtifacts {
     stdlibBuildTask = project.findKonanBuildTask("stdlib", project.platformManager.hostPlatform.target).apply {
         configure {
             dependsOn(":kotlin-native:distCompiler")
-            outputs.dir(project.buildDir.resolve("stdlib/$hostName/stdlib"))
         }
     }
 }

kotlin-native/tools/kotlin-native-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/konan/tasks/KonanCompileTask.kt

@@ -391,6 +391,18 @@ open class KonanCompileFrameworkTask: KonanCompileNativeBinary() {
 }
 
 open class KonanCompileLibraryTask: KonanCompileTask() {
+    override val artifact: File
+        @Internal get() = destinationDir.resolve(artifactFullName)
+
+    val artifactFile: File?
+        @Optional @OutputFile get() = if (!noPack) artifact else null
+
+    val artifactDirectory: File?
+        @Optional @OutputDirectory get() = if (noPack) artifact else null
+
+    override val artifactSuffix: String
+        @Internal get() = if (!noPack) produce.suffix(konanTarget) else ""
+
     override fun buildCommonArgs() = super.buildCommonArgs().apply {
         addKey("-nopack", noPack)
     }