JS: fixed <Type>Array.iterator methods; added -Xtypedarray compiler key

The <Type>Array.iterator used to lack next<Type>() method (KT-16626).

The -Xtypedarray compiler key enables translation of primitive arrays
to TypedArrays, and primitive array`is`-checks (KT-15358, KT-14007,
KT-14614, KT-16056).

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JSCompilerArguments.java

@@ -71,6 +71,10 @@ public class K2JSCompilerArguments extends CommonCompilerArguments {
     @ValueDescription("<path>")
     public String outputPostfix;
 
+    @GradleOption(DefaultValues.BooleanFalseDefault.class)
+    @Argument(value = "Xtypedarrays", description = "Translate primitive arrays to JS typed arrays")
+    public boolean typedArrays;
+
     @NotNull
     public static K2JSCompilerArguments createDefaultInstance() {
         K2JSCompilerArguments arguments = new K2JSCompilerArguments();

compiler/cli/src/org/jetbrains/kotlin/cli/js/K2JSCompiler.java

@@ -286,6 +286,10 @@ public class K2JSCompiler extends CLICompiler<K2JSCompilerArguments> {
             ContainerUtil.addAllNotNull(libraries, arguments.libraries.split(File.pathSeparator));
         }
 
+        if (arguments.typedArrays) {
+            configuration.put(JSConfigurationKeys.TYPED_ARRAYS_ENABLED, true);
+        }
+
         configuration.put(JSConfigurationKeys.LIBRARIES, libraries);
 
         String moduleKindName = arguments.moduleKind;