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

src/backend/commands/analyze.c

@@ -17,7 +17,7 @@
 #include <math.h>
 
 #include "access/detoast.h"
-#include "access/indexgenam.h"
+#include "access/genam.h"
 #include "access/multixact.h"
 #include "access/relation.h"
 #include "access/sysattr.h"

src/backend/commands/cluster.c

@@ -17,8 +17,8 @@
  */
 #include "postgres.h"
 
+#include "access/amapi.h"
 #include "access/heapam.h"
-#include "access/indexam.h"
 #include "access/multixact.h"
 #include "access/relscan.h"
 #include "access/tableam.h"

src/backend/commands/comment.c

@@ -14,8 +14,8 @@
 
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/relation.h"
 #include "access/table.h"
 #include "catalog/indexing.h"

src/backend/commands/constraint.c

@@ -13,8 +13,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/heapam.h"
-#include "access/indexgenam.h"
 #include "access/tableam.h"
 #include "catalog/index.h"
 #include "commands/trigger.h"

src/backend/commands/dbcommands.c

@@ -23,9 +23,9 @@
 #include <unistd.h>
 #include <sys/stat.h>
 
+#include "access/genam.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/multixact.h"
 #include "access/tableam.h"
 #include "access/xact.h"

src/backend/commands/extension.c

@@ -29,8 +29,8 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/relation.h"
 #include "access/sysattr.h"
 #include "access/table.h"

src/backend/commands/functioncmds.c

@@ -32,8 +32,8 @@
  */
 #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/catalog.h"

src/backend/commands/indexcmds.c

@@ -15,9 +15,9 @@
 
 #include "postgres.h"
 
+#include "access/amapi.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
-#include "access/indexam.h"
 #include "access/reloptions.h"
 #include "access/sysattr.h"
 #include "access/tableam.h"

src/backend/commands/matview.c

@@ -14,9 +14,9 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/multixact.h"
 #include "access/tableam.h"
 #include "access/xact.h"

src/backend/commands/opclasscmds.c

@@ -17,9 +17,9 @@
 
 #include <limits.h>
 
+#include "access/genam.h"
 #include "access/hash.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/nbtree.h"
 #include "access/sysattr.h"
 #include "access/table.h"

src/backend/commands/policy.c

@@ -12,9 +12,9 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/relation.h"
 #include "access/sysattr.h"
 #include "access/table.h"

src/backend/commands/proclang.c

@@ -13,8 +13,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/table.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"

src/backend/commands/publicationcmds.c

@@ -14,8 +14,8 @@
 
 #include "postgres.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"

src/backend/commands/seclabel.c

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

src/backend/commands/tablecmds.c

@@ -15,9 +15,9 @@
 #include "postgres.h"
 
 #include "access/attmap.h"
+#include "access/genam.h"
 #include "access/heapam.h"
 #include "access/heapam_xlog.h"
-#include "access/indexgenam.h"
 #include "access/multixact.h"
 #include "access/reloptions.h"
 #include "access/relscan.h"

src/backend/commands/trigger.c

@@ -13,8 +13,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/relation.h"
 #include "access/sysattr.h"
 #include "access/table.h"

src/backend/commands/tsearchcmds.c

@@ -17,8 +17,8 @@
 
 #include <ctype.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"

src/backend/commands/typecmds.c

@@ -31,9 +31,9 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/tableam.h"
 #include "access/xact.h"
 #include "catalog/binary_upgrade.h"

src/backend/commands/user.c

@@ -12,8 +12,8 @@
  */
 #include "postgres.h"
 
+#include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/table.h"
 #include "access/xact.h"
 #include "catalog/binary_upgrade.h"

src/backend/commands/vacuum.c

@@ -24,9 +24,9 @@
 
 #include "access/clog.h"
 #include "access/commit_ts.h"
+#include "access/genam.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"
-#include "access/indexgenam.h"
 #include "access/multixact.h"
 #include "access/tableam.h"
 #include "access/transam.h"