use of arguments is assumed to create side-effects

src/utils/testForSideEffects.js

@@ -24,7 +24,9 @@ export default function testForSideEffects ( node, scope, statement, strongDepen
 			if ( isReference( node, parent ) ) {
 				const flattened = flatten( node );
 
-				if ( !scope.contains( flattened.name ) ) {
+				if ( flattened.name === 'arguments' ) {
+					hasSideEffect = true;
+				} if ( !scope.contains( flattened.name ) ) {
 					const declaration = statement.module.trace( flattened.name );
 					if ( declaration && !declaration.isExternal ) {
 						const module = declaration.module || declaration.statement.module; // TODO is this right?

test/form/side-effect-k/_config.js

@@ -0,0 +1,8 @@
+module.exports = {
+	solo: true,
+	show: true,
+	description: 'use of arguments is treated as a side-effect',
+	options: {
+		moduleName: 'myBundle'
+	}
+};

test/form/side-effect-k/_expected/amd.js

@@ -0,0 +1,5 @@
+define(function () { 'use strict';
+
+	
+
+});

test/form/side-effect-k/_expected/cjs.js

@@ -0,0 +1 @@
+'use strict';

test/form/side-effect-k/foo.js

@@ -0,0 +1,19 @@
+export function augment ( x ) {
+	var prop, source;
+
+	var i = arguments.length;
+	var sources = Array( i - 1 );
+	while ( i-- ) {
+		sources[i-1] = arguments[i];
+	}
+
+	while (source = sources.shift()) {
+		for (prop in source) {
+			if (hasOwn.call(source, prop)) {
+				x[prop] = source[prop];
+			}
+		}
+	}
+
+	return x;
+}

test/form/side-effect-k/main.js

@@ -0,0 +1,4 @@
+import { augment } from './foo.js';
+
+export default function x () {}
+augment( x.prototype );