[JS IR] Review remarks

- Move origin to common place
- Add comments and todo about solution
- Remove MODULE directive from tests
- Add test with in-place using of js function

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/Dce.kt

@@ -386,11 +386,19 @@ fun usefulDeclarations(roots: Iterable<IrDeclaration>, context: JsIrBackendConte
                             val ref = expression.getTypeArgument(0)!!.classifierOrFail.owner as IrDeclaration
                             ref.enqueue("intrinsic: jsClass")
                             referencedJsClasses += ref
-                            if (expression.origin == ClassReferenceLowering.Companion.CLASS_REFERENCE) {
+                            // When class reference provided as parameter to external function
+                            // It can be instantiated by external JS script
+                            // Need to leave constructor for this
+                            // https://youtrack.jetbrains.com/issue/KT-46672
+                            // TODO: Possibly solution with origin is not so good
+                            //  There is option with applying this hack to jsGetKClass
+                            if (expression.origin == JsLoweredDeclarationOrigin.CLASS_REFERENCE) {
+                                // Maybe we need to filter primary constructor
+                                // Although at this time, we should have only primary constructor
                                 (ref as IrClass)
                                     .constructors
                                     .forEach {
-                                        it.enqueue("intrinsic: jsClass constructor")
+                                        it.enqueue("intrinsic: jsClass (constructor)")
                                     }
                             }
                         }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/DeclarationOrigins.kt

@@ -17,4 +17,5 @@ object JsLoweredDeclarationOrigin : IrDeclarationOrigin {
     object BRIDGE_WITHOUT_STABLE_NAME : IrDeclarationOriginImpl("BRIDGE_WITHOUT_STABLE_NAME")
     object OBJECT_GET_INSTANCE_FUNCTION : IrDeclarationOriginImpl("OBJECT_GET_INSTANCE_FUNCTION")
     object JS_SHADOWED_EXPORT : IrDeclarationOriginImpl("JS_SHADOWED_EXPORT")
+    object CLASS_REFERENCE : IrStatementOriginImpl("CLASS_REFERENCE")
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ClassReferenceLowering.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.backend.common.BodyLoweringPass
 import org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext
 import org.jetbrains.kotlin.backend.common.ir.Symbols
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.backend.js.JsLoweredDeclarationOrigin
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.backend.js.utils.toJsArrayLiteral
 import org.jetbrains.kotlin.ir.declarations.*
@@ -130,7 +131,7 @@ class ClassReferenceLowering(val context: JsIrBackendContext) : BodyLoweringPass
         JsIrBuilder.buildCall(
             intrinsics.jsClass,
             typeArguments = listOf(type),
-            origin = CLASS_REFERENCE
+            origin = JsLoweredDeclarationOrigin.CLASS_REFERENCE
         )
 
     private fun buildCall(name: IrSimpleFunctionSymbol, vararg args: IrExpression): IrExpression =
@@ -256,9 +257,5 @@ class ClassReferenceLowering(val context: JsIrBackendContext) : BodyLoweringPass
                 }
         })
     }
-
-    companion object {
-        object CLASS_REFERENCE : IrStatementOriginImpl("CLASS_REFERENCE")
-    }
 }