[test] Add find-index.js to the list of resources for the test

R=jgruber@chromium.org

Bug: chromium:791045, v8:1956, v8:7165
Change-Id: I58ba09248824f0309a3d37afa3e59bdea7c5f1f1
Reviewed-on: https://chromium-review.googlesource.com/813914Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49933}

test/js-perf-test/JSTests.json

@@ -380,7 +380,8 @@
       "main": "run.js",
       "resources": [
         "filter.js", "map.js", "every.js", "join.js", "some.js",
-        "reduce.js", "reduce-right.js", "to-string.js", "find.js"
+        "reduce.js", "reduce-right.js", "to-string.js", "find.js",
+        "find-index.js"
       ],
       "flags": [
         "--allow-natives-syntax"