Add benchmark for temporary object creation

Author: HalidOdat

core/engine/benches/bench_scripts/string_code_point_sum.js

@@ -0,0 +1,8 @@
+(() => {
+  let sum = '';
+  let string = "Hello, world!!!";
+  for (let i = 0; i < string.length; ++i) {
+    sum += string.charCodeAt(i).toString(16);
+  }
+  return sum;
+})();

core/engine/benches/full.rs

@@ -95,6 +95,7 @@ macro_rules! full_benchmarks {
 }
 
 full_benchmarks!(
+    {"String Code Point Sum", string_code_point_sum},
     {"Symbols", symbol_creation},
     {"For loop", for_loop},
     {"Fibonacci", fibonacci},