Make RE2::Options copyable

(There seems to be little reason to block copying a 24 byte struct.)

Change-Id: I6002bfeb7e2598aa827cd42e951e5d59f8c198b4
Reviewed-on: https://code-review.googlesource.com/4891
Reviewed-by: Paul Wankadia <junyer@google.com>
1 file changed