Remove let keyword in front of local definition.

bench-sieve.txt

@@ -3,7 +3,7 @@
 // 178589010 nodes evaluated in 2.126711 seconds = 83974273 nodes/sec
 
 numbers = 8192; // 1028 primes
-repeats = 200;
+repeats = 10; // 200;
 
 count = 0;
 
@@ -13,7 +13,7 @@ evals = evaluations();
 
 for (n = 0;  n < repeats;  n = n + 1) {
     print("\r", n, "/", repeats);
-    let sieve = [];
+    sieve = [];
     count = 0;
     for (i in numbers) sieve.push(nil);
     for (i = 2; i < numbers;  i = i + 1) {