Update test262.

Rolling v8/test/test262/data: https://chromium.googlesource.com/external/github.com/tc39/test262/+log/7dc9215..6c2503a

TBR=adamk@chromium.org,gsathya@chromium.org

Change-Id: I3570f7a9c1e553ea124eea3cf2381dd9a2659fef
Reviewed-on: https://chromium-review.googlesource.com/1111902Reviewed-by: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: V8 Autoroller <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#53971}

DEPS

@@ -58,7 +58,7 @@ deps = {
   'v8/test/mozilla/data':
     Var('chromium_url') + '/v8/deps/third_party/mozilla-tests.git' + '@' + 'f6c578a10ea707b1a8ab0b88943fe5115ce2b9be',
   'v8/test/test262/data':
-    Var('chromium_url') + '/external/github.com/tc39/test262.git' + '@' + '7dc92154af01c6772b1a773e1e9fcb706b863de0',
+    Var('chromium_url') + '/external/github.com/tc39/test262.git' + '@' + '6c2503a810973ccc66deb40dd2e8fb60ce57480f',
   'v8/test/test262/harness':
     Var('chromium_url') + '/external/github.com/test262-utils/test262-harness-py.git' + '@' + '0f2acdd882c84cff43b9d60df7574a1901e2cdcd',
   'v8/tools/clang':