Update .gitignore to new test262 package name.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/188923003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19707 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

.gitignore

@@ -47,7 +47,7 @@ shell_g
 /test/mozilla/data
 /test/mozilla/downloaded_*
 /test/test262/data
-/test/test262/test262-*
+/test/test262/tc39-test262-*
 /third_party
 /tools/jsfunfuzz
 /tools/jsfunfuzz.zip