[K/JS] Move ES modules logic to a new transformer with IC

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/KotlinJsTarget.kt

@@ -183,4 +183,8 @@ constructor(
             }
         }
     }
+
+    override fun useEsModules() {
+        error("ES modules are not supported in legacy JS compiler. Please, use IR one instead.")
+    }
 }

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/dsl/KotlinJsTargetDsl.kt

@@ -53,6 +53,7 @@ interface KotlinJsTargetDsl : KotlinTarget {
     }
 
     fun useCommonJs()
+    fun useEsModules()
 
     val binaries: KotlinJsBinaryContainer
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrTarget.kt

@@ -358,9 +358,30 @@ constructor(
         legacyTarget?.useCommonJs()
     }
 
+    override fun useEsModules() {
+        compilations.all {
+            it.kotlinOptions.configureEsModulesOptions()
+
+            binaries
+                .withType(JsIrBinary::class.java)
+                .all {
+                    it.linkTask.configure { linkTask ->
+                        linkTask.kotlinOptions.configureEsModulesOptions()
+                    }
+                }
+        }
+
+    }
+
     private fun KotlinJsOptions.configureCommonJsOptions() {
         moduleKind = "commonjs"
         sourceMap = true
         sourceMapEmbedSources = "never"
     }
+
+    private fun KotlinJsOptions.configureEsModulesOptions() {
+        moduleKind = "es"
+        sourceMap = true
+        sourceMapEmbedSources = "never"
+    }
 }