Create a 'type cache' that keeps track of the data needed for any particular

datatype by array_eq and array_cmp; use this to solve problems with memory
leaks in array indexing support.  The parser's equality_oper and ordering_oper
routines also use the cache.  Change the operator search algorithms to look
for appropriate btree or hash index opclasses, instead of assuming operators
named '<' or '=' have the right semantics.  (ORDER BY ASC/DESC now also look
at opclasses, instead of assuming '<' and '>' are the right things.)  Add
several more index opclasses so that there is no regression in functionality
for base datatypes.  initdb forced due to catalog additions.

src/test/regress/sql/geometry.sql

@@ -152,5 +152,4 @@ SELECT '' AS two, circle(f1)
 SELECT '' AS twentyfour, c1.f1 AS circle, p1.f1 AS point, (p1.f1 <-> c1.f1) AS distance
    FROM CIRCLE_TBL c1, POINT_TBL p1
    WHERE (p1.f1 <-> c1.f1) > 0
-   ORDER BY distance, circle, point using <<;
-
+   ORDER BY distance, circle using <, point using <<;