[K/JS] Support eager initialization for per-file granularity

js/js.ast/src/org/jetbrains/kotlin/js/backend/JsToStringGenerationVisitor.java

@@ -1404,7 +1404,10 @@ public class JsToStringGenerationVisitor extends JsVisitor {
             p.print("}");
         }
 
-        p.print(" from ");
+        if (!(target == JsImport.Target.Effect.INSTANCE)) {
+            p.print(" from ");
+        }
+
         p.print(javaScriptString(jsImport.getModule()));
     }
 

js/js.ast/src/org/jetbrains/kotlin/js/backend/ast/JsImport.kt

@@ -15,6 +15,7 @@ class JsImport(
         get() = (target as Target.Elements).elements
 
     sealed class Target {
+        object Effect : Target()
         class Elements(val elements: MutableList<Element>) : Target()
         class Default(val name: JsNameRef) : Target() {
             constructor(name: String) : this(JsNameRef(name))
@@ -36,6 +37,7 @@ class JsImport(
 
     override fun acceptChildren(visitor: JsVisitor) {
         when (target) {
+            is Target.Effect -> {}
             is Target.All -> visitor.accept(target.alias)
             is Target.Default -> visitor.accept(target.name)
             is Target.Elements -> target.elements.forEach {