[test] Remove obsolete variants of generator JSTests.

R=adamk@chromium.org

Bug: 
Change-Id: I47087c6a15beceb7084079dcf644de7e9ede772c
Reviewed-on: https://chromium-review.googlesource.com/505620Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45342}

test/js-perf-test/JSTests.json

@@ -33,30 +33,6 @@
       "flags": ["--harmony-function-sent"],
       "results_regexp": "^Generators\\-Generators\\(Score\\): (.+)$"
     },
-    {
-      "name": "GeneratorsIgnition",
-      "path": ["Generators"],
-      "main": "run.js",
-      "resources": ["generators.js"],
-      "flags": [
-        "--harmony-function-sent",
-        "--ignition"
-      ],
-      "results_regexp": "^Generators\\-Generators\\(Score\\): (.+)$"
-    },
-    {
-      "name": "GeneratorsIgnitionTurbofan",
-      "path": ["Generators"],
-      "main": "run.js",
-      "resources": ["generators.js"],
-      "flags": [
-        "--harmony-function-sent",
-        "--ignition",
-        "--turbo",
-        "--turbo-from-bytecode"
-      ],
-      "results_regexp": "^Generators\\-Generators\\(Score\\): (.+)$"
-    },
     {
       "name": "RestParameters",
       "path": ["RestParameters"],