Rewrite SQL++ functions.

-Maps SQL function names to internal names.
-Allows SQL++ builtin functions to be case-insensitive.
-Rewrites SQL-92 global aggregates.
-Refactors SQL++ AST visitors.
-Cleans up semantics of COLL_AGG and SQL-92 AGG.

Change-Id: Idb5a7c6780669b27065b0928bec7e4700cfb53a9
Reviewed-on: https://asterix-gerrit.ics.uci.edu/759
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <tillw@apache.org>
diff --git a/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue785.sqlpp b/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue785.sqlpp
index aecafb4..09bd754 100644
--- a/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue785.sqlpp
+++ b/asterix-app/src/test/resources/optimizerts/queries_sqlpp/query-issue785.sqlpp
@@ -105,7 +105,7 @@
             Orders as orders
       where ((orders.o_custkey = customer.c_custkey) and (customer.c_nationkey = n.n_nationkey))
       group by orders.o_orderdate as orderdate,n.n_nationkey as nation_key
-      with  sum as tpch.sum((
+      with  sum as tpch.coll_sum((
             select element o.o_totalprice
             from  orders as o
         ))