Add spread call micro-benchmarks.

test/js-perf-test/JSTests.json

 {
   "name": "JSTests",
   "run_count": 3,
   "run_count_arm": 1,
   "run_count_arm64": 1,
   "timeout": 120,
   "units": "score",
   "total": true,
   "resources": ["base.js"],
   "tests": [
@@ skipping 216 matching lines @@
         {"name": "in--el-str"},
         {"name": "in--NE-el"},
         {"name": "Object.hasOwnProperty--INTERN-prop"},
         {"name": "Object.hasOwnProperty--DEINTERN-prop"},
         {"name": "Object.hasOwnProperty--NE-INTERN-prop"},
         {"name": "Object.hasOwnProperty--NE-DEINTERN-prop"},
         {"name": "Object.hasOwnProperty--el"},
         {"name": "Object.hasOwnProperty--el-str"},
         {"name": "Object.hasOwnProperty--NE-el"}
       ]
+    },
+    {
+      "name": "SixSpeed",

[Michael Achenbach, 2016/11/07 07:34:37]

My usual question: How fast is this? Especially in relation to the other line
items?

[Yang, 2016/11/07 10:32:19]

This is not slower than the other ones, if not faster than most.

+      "path": ["SixSpeed"],
+      "main": "run.js",
+      "resources": [
+        "benchmark.js",
+        "traceur-runtime.js",
+        "SixSpeed/spread/spread__es5.js",
+        "SixSpeed/spread/spread__traceur.js",
+        "SixSpeed/spread/spread__es6.js"
+      ],
+      "results_regexp": "^%s\\(Score\\): (.+)$",
+      "tests": [
+        {"name": "Spread-ES5"},
+        {"name": "Spread-Traceur"},
+        {"name": "Spread-ES6"}
+      ]
     }
   ]
 }