Revert "Rename files and headers related to index AM"

This follows multiple complains from Peter Geoghegan, Andres Freund and
Alvaro Herrera that this issue ought to be dug more before actually
happening, if it happens.

Discussion: https://postgr.es/m/20191226144606.GA5659@alvherre.pgsql

contrib/bloom/blinsert.c

@@ -12,8 +12,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/generic_xlog.h"
-#include "access/indexgenam.h"
 #include "access/tableam.h"
 #include "bloom.h"
 #include "catalog/index.h"

contrib/bloom/bloom.h

@@ -13,8 +13,8 @@
 #ifndef _BLOOM_H_
 #define _BLOOM_H_
 
+#include "access/amapi.h"
 #include "access/generic_xlog.h"
-#include "access/indexam.h"
 #include "access/itup.h"
 #include "access/xlog.h"
 #include "fmgr.h"

contrib/bloom/blutils.c

@@ -13,8 +13,8 @@
  */
 #include "postgres.h"
 
+#include "access/amapi.h"
 #include "access/generic_xlog.h"
-#include "access/indexam.h"
 #include "access/reloptions.h"
 #include "bloom.h"
 #include "catalog/index.h"

contrib/bloom/blvacuum.c

@@ -12,7 +12,7 @@
  */
 #include "postgres.h"
 
-#include "access/indexgenam.h"
+#include "access/genam.h"
 #include "bloom.h"
 #include "catalog/storage.h"
 #include "commands/vacuum.h"

contrib/bloom/blvalidate.c

@@ -12,8 +12,8 @@
  */
 #include "postgres.h"
 
+#include "access/amvalidate.h"
 #include "access/htup_details.h"
-#include "access/indexamvalidate.h"
 #include "bloom.h"
 #include "catalog/pg_amop.h"
 #include "catalog/pg_amproc.h"

contrib/sepgsql/database.c

@@ -10,8 +10,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/sysattr.h"
 #include "access/table.h"
 #include "catalog/dependency.h"

contrib/sepgsql/label.c

@@ -12,8 +12,8 @@
 
 #include <selinux/label.h>
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/table.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"

contrib/sepgsql/proc.c

@@ -10,8 +10,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/sysattr.h"
 #include "access/table.h"
 #include "catalog/dependency.h"

contrib/sepgsql/relation.c

@@ -10,8 +10,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/sysattr.h"
 #include "access/table.h"
 #include "catalog/dependency.h"

contrib/sepgsql/schema.c

@@ -10,8 +10,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/sysattr.h"
 #include "access/table.h"
 #include "catalog/dependency.h"