add micro-benchmark for Proxy with isExtensible trap

Bug: v8:6664
Change-Id: Ie320264cfba8c33c90405bb009f584b8e2b3d8ce
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1637660Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#61969}

test/js-perf-test/JSTests4.json

@@ -33,7 +33,9 @@
         {"name": "SetIndexWithTrap"},
         {"name": "SetSymbolWithoutTrap"},
         {"name": "SetSymbolWithTrap"},
-        {"name": "HasInIdiom"}
+        {"name": "HasInIdiom"},
+        {"name": "IsExtensibleWithoutTrap"},
+        {"name": "IsExtensibleWithTrap"}
       ]
     },
     {

test/js-perf-test/Proxies/proxies.js

@@ -506,3 +506,47 @@ newBenchmark("HasInIdiom", {
     return result === 20 * SOME_NUMBER;
   }
 });
+
+// ----------------------------------------------------------------------------
+
+obj = {};
+value = false;
+
+newBenchmark("IsExtensibleWithoutTrap", {
+  setup() {
+    p = new Proxy(obj, {});
+  },
+  run() {
+    for(var i = 0; i < ITERATIONS; i++) {
+      value = Object.isExtensible(p);
+    }
+    return value;
+  },
+  teardown() {
+    return value === true;
+  }
+});
+
+// ----------------------------------------------------------------------------
+
+obj = {};
+value = false;
+
+newBenchmark("IsExtensibleWithTrap", {
+  setup() {
+    p = new Proxy(obj, {
+      isExtensible: function(target) {
+        return true;
+      }
+    });
+  },
+  run() {
+    for(var i = 0; i < ITERATIONS; i++) {
+      value = Object.isExtensible(p);
+    }
+    return value;
+  },
+  teardown() {
+    return value === true;
+  }
+});