[Gradle, JS] Compatibility with lower than 4.9

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrSubTarget.kt

@@ -96,7 +96,7 @@ abstract class KotlinJsIrSubTarget(
             testJs.group = LifecycleBasePlugin.VERIFICATION_GROUP
             testJs.description = testTaskDescription
 
-            testJs.inputFileProperty.set(compilation.developmentLinkTask.flatMap { it.outputFileProperty })
+            testJs.inputFileProperty.set(compilation.developmentLinkTask.map { it.outputFileProperty.get() })
 
             testJs.dependsOn(nodeJs.npmInstallTask, nodeJs.nodeJsSetupTask)
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinNodeJsIr.kt

@@ -34,7 +34,7 @@ open class KotlinNodeJsIr @Inject constructor(target: KotlinJsIrTarget) :
         compilation: KotlinJsIrCompilation
     ) {
         val runTaskHolder = NodeJsExec.create(compilation, disambiguateCamelCased(RUN_TASK_NAME)) {
-            inputFileProperty.set(compilation.developmentLinkTask.flatMap { it.outputFileProperty })
+            inputFileProperty.set(compilation.developmentLinkTask.map { it.outputFileProperty.get() })
         }
         target.runTask.dependsOn(runTaskHolder)
     }