LibJS: Add test for well-known symbols

Author: https://github.com/mattco98
Commit: 9783a4936c
Pull-request: https://github.com/SerenityOS/serenity/pull/2723
Issue: https://github.com/SerenityOS/serenity/issues/2709
Reviewed-by: https://github.com/awesomekling

Libraries/LibJS/Tests/builtins/Symbol/well-known-symbol-existence.js

@@ -0,0 +1,15 @@
+test("basic functionality", () => {
+    expect(Symbol).toHaveProperty("iterator");
+    expect(Symbol).toHaveProperty("asyncIterator");
+    expect(Symbol).toHaveProperty("match");
+    expect(Symbol).toHaveProperty("matchAll");
+    expect(Symbol).toHaveProperty("replace");
+    expect(Symbol).toHaveProperty("search");
+    expect(Symbol).toHaveProperty("split");
+    expect(Symbol).toHaveProperty("hasInstance");
+    expect(Symbol).toHaveProperty("isConcatSpreadable");
+    expect(Symbol).toHaveProperty("unscopables");
+    expect(Symbol).toHaveProperty("species");
+    expect(Symbol).toHaveProperty("toPrimitive");
+    expect(Symbol).toHaveProperty("toStringTag");
+});