kotlin-test-native-xctest: refine KGP script

use compilerOptions DSL instead of sourceSets

Author: sbogolepov

native/kotlin-test-native-xctest/build.gradle.kts

@@ -112,7 +112,7 @@ kotlin {
 
         forEach {
             val copyTask = registerCopyFrameworkTask(it.konanTarget)
-            it.compilations.getByName("main") {
+            it.compilations.named("main") {
                 cinterops {
                     register("XCTest") {
                         compilerOpts("-iframework", copyTask.map { it.destinationDir }.get().absolutePath)
@@ -125,13 +125,11 @@ kotlin {
             }
         }
     }
-    sourceSets.all {
-        languageSettings.apply {
-            // Oh, yeah! So much experimental, so wow!
-            optIn("kotlinx.cinterop.BetaInteropApi")
-            optIn("kotlinx.cinterop.ExperimentalForeignApi")
-            optIn("kotlin.experimental.ExperimentalNativeApi")
-        }
+
+    compilerOptions {
+        optIn.add("kotlinx.cinterop.BetaInteropApi")
+        optIn.add("kotlinx.cinterop.ExperimentalForeignApi")
+        optIn.add("kotlin.experimental.ExperimentalNativeApi")
     }
 }