LibJS: Disallow 'with' statement in strict mode

Author: https://github.com/linusg
Commit: 3ac7fb9f6c
Pull-request: https://github.com/SerenityOS/serenity/pull/4205

Libraries/LibJS/Tests/with-basic.js

@@ -18,3 +18,7 @@ test("basic with statement functionality", () => {
 
     expect(bar).toBe(99);
 });
+
+test("syntax error in strict mode", () => {
+    expect("'use strict'; with (foo) {}").not.toEval();
+});