[JS IR BE] Make kotlinx.io compile

- Fix expect/actual default arguments
 - Fix dynamic type in inliner
 - Fix external varargs

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

@@ -87,7 +87,7 @@ private val moveBodilessDeclarationsToSeparatePlacePhase = makeCustomJsModulePha
 )
 
 private val expectDeclarationsRemovingPhase = makeJsModulePhase(
-    ::ExpectDeclarationsRemoving,
+    ::ExpectDeclarationsRemoveLowering,
     name = "ExpectDeclarationsRemoving",
     description = "Remove expect declaration from module fragment"
 )

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

@@ -157,8 +157,10 @@ internal class DeepCopyIrTreeWithSymbolsForInliner(
             if (type !is IrSimpleType) return type
 
             val substitutedType = typeArguments?.get(type.classifier)
-            if (substitutedType != null) {
-                substitutedType as IrSimpleType
+
+            if (substitutedType is IrDynamicType) return substitutedType
+
+            if (substitutedType is IrSimpleType) {
                 return substitutedType.buildSimpleType {
                     kotlinType = null
                     hasQuestionMark = type.hasQuestionMark or substitutedType.isMarkedNullable()

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsExpressionTransformer.kt

@@ -282,6 +282,8 @@ class IrElementToJsExpressionTransformer : BaseIrElementToJsNodeTransformer<JsEx
                 JsInvocation(
                     // Create scope for temporary variable holding dispatch receiver
                     // It is used both during method reference and passing `this` value to `apply` function.
+                    JsNameRef(
+                    "call",
                     JsFunction(
                         context.currentScope,
                         JsBlock(
@@ -297,7 +299,8 @@ class IrElementToJsExpressionTransformer : BaseIrElementToJsNodeTransformer<JsEx
                             )
                         ),
                         "VarargIIFE"
-                    )
+                    )),
+                    JsThisRef()
                 )
             } else {
                 JsInvocation(

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt

@@ -78,7 +78,7 @@ fun translateCallArguments(expression: IrMemberAccessExpression, context: JsGene
         val argument = expression.getValueArgument(index)
         val result = argument?.accept(transformer, context)
         if (result == null) {
-            assert(expression is IrFunctionAccessExpression && expression.symbol.owner.isEffectivelyExternal())
+            require(expression is IrFunctionAccessExpression && expression.symbol.owner.isEffectivelyExternal())
             JsPrefixOperation(JsUnaryOperator.VOID, JsIntLiteral(1))
         } else
             result