[test] Add micro-benchmarks for Map and Set iterators.

Change-Id: I5fc90147ee7526b8b66d04f38e5e225741cf4642
Bug: v8:6571
Reviewed-on: https://chromium-review.googlesource.com/559342Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46412}

test/js-perf-test/Collections/map.js

@@ -32,6 +32,11 @@ var MapIterationBenchmark = new BenchmarkSuite('Map-Iteration', [1000], [
 ]);
 
 
+var MapIterationBenchmark = new BenchmarkSuite('Map-Iterator', [1000], [
+  new Benchmark('Iterator', false, false, 0, MapIterator, MapSetupSmi, MapTearDown),
+]);
+
+
 var map;
 
 
@@ -215,3 +220,10 @@ function MapForEach() {
     }
   });
 }
+
+
+function MapIterator() {
+  var result = 0;
+  for (const v of map.values()) result += v;
+  return result;
+}

test/js-perf-test/Collections/set.js

@@ -29,6 +29,11 @@ var SetIterationBenchmark = new BenchmarkSuite('Set-Iteration', [1000], [
 ]);
 
 
+var SetIterationBenchmark = new BenchmarkSuite('Set-Iterator', [1000], [
+  new Benchmark('Iterator', false, false, 0, SetIterator, SetSetupSmi, SetTearDown),
+]);
+
+
 var set;
 
 
@@ -170,3 +175,10 @@ function SetForEach() {
     }
   });
 }
+
+
+function SetIterator() {
+  var result = 0;
+  for (const v of set) result += v;
+  return result;
+}

test/js-perf-test/JSTests.json

@@ -110,10 +110,12 @@
         {"name": "Map-String"},
         {"name": "Map-Object"},
         {"name": "Map-Iteration"},
+        {"name": "Map-Iterator"},
         {"name": "Set-Smi"},
         {"name": "Set-String"},
         {"name": "Set-Object"},
         {"name": "Set-Iteration"},
+        {"name": "Set-Iterator"},
         {"name": "WeakMap"},
         {"name": "WeakSet"}
       ]