Avoid including tableam.h and xlogreader.h in nbtree.h

Doing that seems rather random and unnecessary.  This commit removes
those and fixes fallout, which is pretty minimal.  We do need to add a
forward declaration of struct TM_IndexDeleteOp (whose full definition
appears in tableam.h) so that _bt_delitems_delete_check()'s declaration
can use it.

Author: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/202508051109.lzk3lcuzsaxo@alvherre.pgsql

contrib/btree_gist/btree_bool.c

@@ -5,6 +5,7 @@
 
 #include "btree_gist.h"
 #include "btree_utils_num.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct boolkey

contrib/btree_gist/btree_cash.c

@@ -7,6 +7,7 @@
 #include "btree_utils_num.h"
 #include "common/int.h"
 #include "utils/cash.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct

contrib/btree_gist/btree_date.c

@@ -7,6 +7,7 @@
 #include "btree_utils_num.h"
 #include "utils/fmgrprotos.h"
 #include "utils/date.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct

contrib/btree_gist/btree_enum.c

@@ -8,6 +8,7 @@
 #include "fmgr.h"
 #include "utils/fmgrprotos.h"
 #include "utils/fmgroids.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 /* enums are really Oids, so we just use the same structure */

contrib/btree_gist/btree_float4.c

@@ -6,6 +6,7 @@
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "utils/float.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct float4key

contrib/btree_gist/btree_float8.c

@@ -6,6 +6,7 @@
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "utils/float.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct float8key

contrib/btree_gist/btree_inet.c

@@ -7,6 +7,7 @@
 #include "btree_utils_num.h"
 #include "catalog/pg_type.h"
 #include "utils/builtins.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct inetkey

contrib/btree_gist/btree_int2.c

@@ -6,6 +6,7 @@
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "common/int.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct int16key

contrib/btree_gist/btree_int4.c

@@ -5,6 +5,7 @@
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "common/int.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct int32key

contrib/btree_gist/btree_int8.c

@@ -6,6 +6,7 @@
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "common/int.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct int64key

contrib/btree_gist/btree_interval.c

@@ -6,6 +6,7 @@
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "utils/fmgrprotos.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 #include "utils/timestamp.h"
 

contrib/btree_gist/btree_macaddr.c

@@ -7,6 +7,7 @@
 #include "btree_utils_num.h"
 #include "utils/fmgrprotos.h"
 #include "utils/inet.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct

contrib/btree_gist/btree_macaddr8.c

@@ -7,6 +7,7 @@
 #include "btree_utils_num.h"
 #include "utils/fmgrprotos.h"
 #include "utils/inet.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct

contrib/btree_gist/btree_oid.c

@@ -5,6 +5,7 @@
 
 #include "btree_gist.h"
 #include "btree_utils_num.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct

contrib/btree_gist/btree_time.c

@@ -7,6 +7,7 @@
 #include "btree_utils_num.h"
 #include "utils/fmgrprotos.h"
 #include "utils/date.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 #include "utils/timestamp.h"
 

contrib/btree_gist/btree_ts.c

@@ -10,6 +10,7 @@
 #include "utils/fmgrprotos.h"
 #include "utils/timestamp.h"
 #include "utils/float.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 
 typedef struct

contrib/btree_gist/btree_utils_var.c

@@ -11,6 +11,7 @@
 #include "btree_utils_var.h"
 #include "mb/pg_wchar.h"
 #include "utils/rel.h"
+#include "varatt.h"
 
 /* used for key sorting */
 typedef struct

contrib/btree_gist/btree_uuid.c

@@ -6,6 +6,7 @@
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "port/pg_bswap.h"
+#include "utils/rel.h"
 #include "utils/sortsupport.h"
 #include "utils/uuid.h"