perf: 15 % better perf for number to string, avoid intermediate Math.abs, use implicit number to string coercion (#28)

* avoid intermediate Math.abs

* format code

* use implicit conversion of numbers

Author: Uzlopak

lib/stringify.js

@@ -13,8 +13,7 @@ function getAsPrimitive(value) {
   } else if (type === "boolean") {
     return value ? "true" : "false";
   } else if (type === "number" && Number.isFinite(value)) {
-    if (Math.abs(value) < 1e21) return value.toString();
-    return encodeString(value.toString());
+    return value < 1e21 ? "" + value : encodeString("" + value);
   }
 
   return "";