Update stringify.js

- Remove toString();
- Combine the boolean and bigint else if blocks

Author: 0o001

lib/stringify.js

@@ -8,10 +8,8 @@ function getAsPrimitive(value) {
   if (type === "string") {
     // Length check is handled inside encodeString function
     return encodeString(value);
-  } else if (type === "bigint") {
-    return value.toString();
-  } else if (type === "boolean") {
-    return value ? "true" : "false";
+  } else if (type === "bigint" || type === "boolean") {
+    return "" + value;
   } else if (type === "number" && Number.isFinite(value)) {
     return value < 1e21 ? "" + value : encodeString("" + value);
   }