Make the fetch_statentries_for_relation routine local again.

Removing machinery on analysing duplicates we don't need this function for now.
Remember, it (and its struct) have been changing, it would be a burden to copy
it inside the extension on such an early stage.

Author: danolivo

src/backend/statistics/extended_stats.c

@@ -75,6 +75,7 @@ typedef struct StatExtEntry
 } StatExtEntry;
 
 
+static List *fetch_statentries_for_relation(Relation pg_statext, Oid relid);
 static VacAttrStats **lookup_var_attr_stats(Relation rel, Bitmapset *attrs, List *exprs,
 											int nvacatts, VacAttrStats **vacatts);
 static void statext_store(Oid statOid, bool inh,
@@ -419,7 +420,7 @@ statext_is_kind_built(HeapTuple htup, char type)
 /*
  * Return a list (of StatExtEntry) of statistics objects for the given relation.
  */
-List *
+static List *
 fetch_statentries_for_relation(Relation pg_statext, Oid relid)
 {
 	SysScanDesc scan;

src/include/statistics/statistics.h

@@ -101,7 +101,6 @@ extern MVNDistinct *statext_ndistinct_load(Oid mvoid, bool inh);
 extern MVDependencies *statext_dependencies_load(Oid mvoid, bool inh);
 extern MCVList *statext_mcv_load(Oid mvoid, bool inh);
 
-extern List *fetch_statentries_for_relation(Relation pg_statext, Oid relid);
 extern void BuildRelationExtStatistics(Relation onerel, bool inh, double totalrows,
 									   int numrows, HeapTuple *rows,
 									   int natts, VacAttrStats **vacattrstats);