[es6] fixup for rest parameters perf test

test/js-perf-test/JSTests.json

 {
   "name": "JSTests",
   "run_count": 5,
   "run_count_android_arm": 3,
   "run_count_android_arm64": 3,
   "timeout": 120,
   "units": "score",
   "total": true,
   "resources": ["base.js"],
   "tests": [
     {
       "name": "RestParameters",
       "path": ["RestParameters"],
       "main": "run.js",
       "resources": ["rest.js"],
       "flags": ["--harmony-rest-parameters"],
       "run_count": 5,
       "units": "score",
       "results_regexp": "^%s\\-RestParameters\\(Score\\): (.+)$",
       "tests": [
-        {"name": "BasicRest1"}
+        {"name": "Basic1"}
       ]
     },
     {
       "name": "SpreadCalls",
       "path": ["SpreadCalls"],
       "main": "run.js",
       "resources": ["spreadcalls.js"],
       "flags": ["--harmony-spreadcalls"],
       "run_count": 5,
       "units": "score",
@@ skipping 102 matching lines @@
       "path": ["Exceptions"],
       "main": "run.js",
       "resources": ["try-catch.js"],
       "results_regexp": "^%s\\-Exceptions\\(Score\\): (.+)$",
       "tests": [
         {"name": "Try-Catch"}
       ]
     }
   ]
 }