THRIFT-575. Allow required fields in function parameters

r665255 was a bit too aggressive.  "optional" was causing confusion,
but there doesn't seem to be any harm in allowing "required".

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@810713 13f79535-47bb-0310-9956-ffa450edef68
1 file changed