Suppress -Wmismtached-tags clang compiler warning(s)
Suppress -Wmismtached-tags clang compiler warning(s)

warning: 'FdbFileHandle' defined as a
    class here but previously declared as a struct [-Wmismatched-tags]

Change-Id: Ife73b4a120bcb16faaf0b13ebf5b07713ae80acf
Reviewed-on: http://review.couchbase.org/64618
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Chiyoung Seo <fcffc23db27b19ee4ebba46695ee6b50e09216a2@couchbase.com>

hisundar/forestdb,couchbase/forestdb,wurikiji/forestdb,hisundar/forestdb,wurikiji/forestdb,couchbase/forestdb