CONTRIBUTORS: add Cherry Zhang (Google CLA)

Change-Id: I4efd109b864869e5069f69847f64a55cd1ac053d
Reviewed-on: https://go-review.googlesource.com/64111
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index fa38084..ccaa9ce 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -30,6 +30,7 @@
 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
 Andreas Schwab <schwab@suse.de>
 Andrew Wilkins <axwalk@gmail.com>
+Cherry Zhang <cherryyz@google.com>
 Chris Manghane <cmang@golang.org>
 Christopher Wedgwood <cw@f00f.org>
 Dave Cheney <dave@cheney.net>