[procname] preserve sharing when serialising

Summary: Given the brittleness of DB-indexing over marshalled values (one example exposed in D23191601), the serializer "for comparison" must be removed.  Serialized procnames are no longer used as keys, so their serializer can be converted to the one which preserves sharing (saving some space in the process).

Reviewed By: jberdine

Differential Revision: D23425123

fbshipit-source-id: 9c82da778

infer/src/IR/Procname.ml

@@ -787,7 +787,7 @@ module SQLite = struct
     let sexp_of_t p = Sexp.Atom (F.asprintf "%a" pp p)
   end
 
-  module Serializer = SqliteUtils.MarshalledDataForComparison (T)
+  module Serializer = SqliteUtils.MarshalledDataNOTForComparison (T)
 
   let pname_to_key = Base.Hashtbl.create (module T)