LibJS: Throw TypeError when coercing symbol to number

Author: https://github.com/linusg
Commit: 4569e88bea
Pull-request: https://github.com/SerenityOS/serenity/pull/2270
Issue: https://github.com/SerenityOS/serenity/issues/2267

Libraries/LibJS/Tests/Symbol.prototype.toString.js

@@ -14,13 +14,12 @@ try {
         message: "Can't convert symbol to string",
     });
     
-    // FIXME: Uncomment when this doesn't assert
-    // assertThrowsError(() => {
-    //     s1 + 1;
-    // }, {
-    //     error: TypeError,
-    //     message: "Can't convert symbol to number",
-    // });
+    assertThrowsError(() => {
+        s1 + 1;
+    }, {
+        error: TypeError,
+        message: "Can't convert symbol to number",
+    });
     
     console.log("PASS");
 } catch (e) {