Move `extractNames` to its own file

src/Module.js

@@ -10,7 +10,7 @@ import SOURCEMAPPING_URL from './utils/sourceMappingURL.js';
 import { SyntheticDefaultDeclaration, SyntheticNamespaceDeclaration } from './Declaration.js';
 import { isFalsy, isTruthy } from './ast/conditions.js';
 import { emptyBlockStatement } from './ast/create.js';
-import { extractNames } from './ast/Scope.js';
+import extractNames from './ast/extractNames.js';
 
 export default class Module {
 	constructor ({ id, code, originalCode, ast, sourceMapChain, bundle }) {

src/ast/Scope.js

@@ -1,37 +1,6 @@
 import { blank, keys } from '../utils/object.js';
 import Declaration from '../Declaration.js';
-
-const extractors = {
-	Identifier ( names, param ) {
-		names.push( param.name );
-	},
-
-	ObjectPattern ( names, param ) {
-		param.properties.forEach( prop => {
-			extractors[ prop.value.type ]( names, prop.value );
-		});
-	},
-
-	ArrayPattern ( names, param ) {
-		param.elements.forEach( element => {
-			if ( element ) extractors[ element.type ]( names, element );
-		});
-	},
-
-	RestElement ( names, param ) {
-		extractors[ param.argument.type ]( names, param.argument );
-	},
-
-	AssignmentPattern ( names, param ) {
-		extractors[ param.left.type ]( names, param.left );
-	}
-};
-
-export function extractNames ( param ) {
-	const names = [];
-	extractors[ param.type ]( names, param );
-	return names;
-}
+import extractNames from './extractNames.js';
 
 export default class Scope {
 	constructor ( options ) {

src/ast/extractNames.js

@@ -0,0 +1,31 @@
+export default function extractNames ( param ) {
+	const names = [];
+	extractors[ param.type ]( names, param );
+	return names;
+}
+
+const extractors = {
+	Identifier ( names, param ) {
+		names.push( param.name );
+	},
+
+	ObjectPattern ( names, param ) {
+		param.properties.forEach( prop => {
+			extractors[ prop.value.type ]( names, prop.value );
+		});
+	},
+
+	ArrayPattern ( names, param ) {
+		param.elements.forEach( element => {
+			if ( element ) extractors[ element.type ]( names, element );
+		});
+	},
+
+	RestElement ( names, param ) {
+		extractors[ param.argument.type ]( names, param.argument );
+	},
+
+	AssignmentPattern ( names, param ) {
+		extractors[ param.left.type ]( names, param.left );
+	}
+};