[Gradle, JS] Turn on by default sourcemap generation for JS IR

#KT-46551 Fixed

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -228,5 +228,7 @@ constructor(
 
     private fun KotlinJsOptions.configureCommonJsOptions() {
         moduleKind = "commonjs"
+        sourceMap = true
+        sourceMapEmbedSources = "never"
     }
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -126,6 +126,8 @@ open class KotlinJsIrTargetConfigurator() :
 
     private fun KotlinJsOptions.configureOptions() {
         moduleKind = "umd"
+        sourceMap = true
+        sourceMapEmbedSources = "never"
     }
 
     override fun defineConfigurationsForTarget(target: KotlinJsIrTarget) {