LazyKotlincDistDownloaderAndUnpacker: put js.engines.jar from bundled dist

GitOrigin-RevId: bde338ae3d8c57589303effaea17827f80b3efe9

plugins/kotlin/base/plugin/src/org/jetbrains/kotlin/idea/compiler/configuration/KotlinPluginLayout.kt

@@ -29,6 +29,10 @@ sealed class KotlinPluginLayout {
      */
     abstract val jpsPluginClasspath: List<File>
 
+    val jsEngines by lazy {
+        kotlinc.resolve("lib").resolve("js.engines.jar").also { check(it.exists()) { "$it doesn't exist" } }
+    }
+
     /**
      * Version of the stand-alone compiler (artifacts in the 'kotlinc/' directory of the Kotlin plugin).
      * Stand-alone compiler is always stable in 'master' and release branches. It is used for compilation with JPS.

plugins/kotlin/base/plugin/src/org/jetbrains/kotlin/idea/compiler/configuration/LazyKotlincDistDownloaderAndUnpacker.kt

@@ -62,6 +62,8 @@ private class LazyDistDirLayoutProducer(version: String, private val unpackedDis
         for (jarInMavenRepo in input) {
             jarInMavenRepo.copyTo(lib.resolve(getDistJarNameFromMavenJar(jarInMavenRepo) ?: continue))
         }
+        val jsEngines = KotlinPluginLayout.instance.jsEngines
+        jsEngines.copyTo(lib.resolve(jsEngines.name)) // js.engines is required to avoid runtime errors when compiling kts via JPS
         return listOf(unpackedDistDestination)
     }