Remove unused #include's from backend .c files

as determined by include-what-you-use (IWYU)

While IWYU also suggests to *add* a bunch of #include's (which is its
main purpose), this patch does not do that.  In some cases, a more
specific #include replaces another less specific one.

Some manual adjustments of the automatic result:

- IWYU currently doesn't know about includes that provide global
  variable declarations (like -Wmissing-variable-declarations), so
  those includes are being kept manually.

- All includes for port(ability) headers are being kept for now, to
  play it safe.

- No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the
  patch from exploding in size.

Note that this patch touches just *.c files, so nothing declared in
header files changes in hidden ways.

As a small example, in src/backend/access/transam/rmgr.c, some IWYU
pragma annotations are added to handle a special case there.

Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org

src/backend/storage/buffer/buf_table.c

@@ -22,7 +22,6 @@
 #include "postgres.h"
 
 #include "storage/buf_internals.h"
-#include "storage/bufmgr.h"
 
 /* entry for buffer lookup hashtable */
 typedef struct

src/backend/storage/buffer/bufmgr.c

@@ -36,7 +36,6 @@
 #include "access/tableam.h"
 #include "access/xloginsert.h"
 #include "access/xlogutils.h"
-#include "catalog/catalog.h"
 #include "catalog/storage.h"
 #include "catalog/storage_xlog.h"
 #include "executor/instrument.h"

src/backend/storage/buffer/localbuf.c

@@ -16,7 +16,6 @@
 #include "postgres.h"
 
 #include "access/parallel.h"
-#include "catalog/catalog.h"
 #include "executor/instrument.h"
 #include "pgstat.h"
 #include "storage/buf_internals.h"

src/backend/storage/file/buffile.c

@@ -49,8 +49,8 @@
 #include "executor/instrument.h"
 #include "miscadmin.h"
 #include "pgstat.h"
-#include "storage/buf_internals.h"
 #include "storage/buffile.h"
+#include "storage/bufmgr.h"
 #include "storage/fd.h"
 #include "utils/resowner.h"
 

src/backend/storage/file/fileset.c

@@ -23,14 +23,11 @@
 
 #include <limits.h>
 
-#include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
 #include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
-#include "storage/ipc.h"
 #include "storage/fileset.h"
-#include "utils/builtins.h"
 
 static void FileSetPath(char *path, FileSet *fileset, Oid tablespace);
 static void FilePath(char *path, FileSet *fileset, const char *name);

src/backend/storage/file/sharedfileset.c

@@ -20,14 +20,8 @@
 
 #include <limits.h>
 
-#include "catalog/pg_tablespace.h"
-#include "commands/tablespace.h"
-#include "common/hashfn.h"
-#include "miscadmin.h"
 #include "storage/dsm.h"
-#include "storage/ipc.h"
 #include "storage/sharedfileset.h"
-#include "utils/builtins.h"
 
 static void SharedFileSetOnDetach(dsm_segment *segment, Datum datum);
 

src/backend/storage/freespace/freespace.c

@@ -29,8 +29,8 @@
 #include "miscadmin.h"
 #include "storage/freespace.h"
 #include "storage/fsm_internals.h"
-#include "storage/lmgr.h"
 #include "storage/smgr.h"
+#include "utils/rel.h"
 
 
 /*

src/backend/storage/ipc/dsm.c

@@ -44,7 +44,6 @@
 #include "storage/pg_shmem.h"
 #include "storage/shmem.h"
 #include "utils/freepage.h"
-#include "utils/guc.h"
 #include "utils/memutils.h"
 #include "utils/resowner.h"
 

src/backend/storage/ipc/ipci.c

@@ -16,7 +16,6 @@
 
 #include "access/clog.h"
 #include "access/commit_ts.h"
-#include "access/heapam.h"
 #include "access/multixact.h"
 #include "access/nbtree.h"
 #include "access/subtrans.h"
@@ -53,8 +52,6 @@
 #include "storage/spin.h"
 #include "utils/guc.h"
 #include "utils/injection_point.h"
-#include "utils/snapmgr.h"
-#include "utils/wait_event.h"
 
 /* GUCs */
 int			shared_memory_type = DEFAULT_SHARED_MEMORY_TYPE;

src/backend/storage/ipc/latch.c

@@ -60,7 +60,6 @@
 #include "storage/ipc.h"
 #include "storage/latch.h"
 #include "storage/pmsignal.h"
-#include "storage/shmem.h"
 #include "utils/memutils.h"
 #include "utils/resowner.h"
 

src/backend/storage/ipc/procarray.c

@@ -47,7 +47,6 @@
 
 #include <signal.h>
 
-#include "access/clog.h"
 #include "access/subtrans.h"
 #include "access/transam.h"
 #include "access/twophase.h"

src/backend/storage/ipc/procsignal.c

@@ -27,7 +27,6 @@
 #include "storage/condition_variable.h"
 #include "storage/ipc.h"
 #include "storage/latch.h"
-#include "storage/proc.h"
 #include "storage/shmem.h"
 #include "storage/smgr.h"
 #include "storage/sinval.h"

src/backend/storage/ipc/shm_mq.c

@@ -22,7 +22,6 @@
 #include "pgstat.h"
 #include "port/pg_bitutils.h"
 #include "postmaster/bgworker.h"
-#include "storage/procsignal.h"
 #include "storage/shm_mq.h"
 #include "storage/spin.h"
 #include "utils/memutils.h"

src/backend/storage/ipc/shmem.c

@@ -65,7 +65,6 @@
 
 #include "postgres.h"
 
-#include "access/transam.h"
 #include "fmgr.h"
 #include "funcapi.h"
 #include "miscadmin.h"

src/backend/storage/ipc/signalfuncs.c

@@ -24,7 +24,7 @@
 #include "storage/proc.h"
 #include "storage/procarray.h"
 #include "utils/acl.h"
-#include "utils/builtins.h"
+#include "utils/fmgrprotos.h"
 
 
 /*

src/backend/storage/ipc/sinval.c

@@ -15,10 +15,8 @@
 #include "postgres.h"
 
 #include "access/xact.h"
-#include "commands/async.h"
 #include "miscadmin.h"
-#include "storage/ipc.h"
-#include "storage/proc.h"
+#include "storage/latch.h"
 #include "storage/sinvaladt.h"
 #include "utils/inval.h"
 

src/backend/storage/ipc/standby.c

@@ -26,13 +26,11 @@
 #include "pgstat.h"
 #include "replication/slot.h"
 #include "storage/bufmgr.h"
-#include "storage/lmgr.h"
 #include "storage/proc.h"
 #include "storage/procarray.h"
 #include "storage/sinvaladt.h"
 #include "storage/standby.h"
 #include "utils/hsearch.h"
-#include "utils/memutils.h"
 #include "utils/ps_status.h"
 #include "utils/timeout.h"
 #include "utils/timestamp.h"

src/backend/storage/large_object/inv_api.c

@@ -35,7 +35,6 @@
 #include "access/detoast.h"
 #include "access/genam.h"
 #include "access/htup_details.h"
-#include "access/sysattr.h"
 #include "access/table.h"
 #include "access/xact.h"
 #include "catalog/dependency.h"

src/backend/storage/lmgr/condition_variable.c

@@ -21,11 +21,9 @@
 #include "miscadmin.h"
 #include "portability/instr_time.h"
 #include "storage/condition_variable.h"
-#include "storage/ipc.h"
 #include "storage/proc.h"
 #include "storage/proclist.h"
 #include "storage/spin.h"
-#include "utils/memutils.h"
 
 /* Initially, we are not prepared to sleep on any condition variable. */
 static ConditionVariable *cv_sleep_target = NULL;

src/backend/storage/lmgr/lmgr.c

@@ -16,7 +16,6 @@
 #include "postgres.h"
 
 #include "access/subtrans.h"
-#include "access/transam.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"
 #include "commands/progress.h"

src/backend/storage/lmgr/lock.c

@@ -35,12 +35,10 @@
 #include "access/transam.h"
 #include "access/twophase.h"
 #include "access/twophase_rmgr.h"
-#include "access/xact.h"
 #include "access/xlog.h"
 #include "access/xlogutils.h"
 #include "miscadmin.h"
 #include "pg_trace.h"
-#include "pgstat.h"
 #include "storage/proc.h"
 #include "storage/procarray.h"
 #include "storage/sinvaladt.h"

src/backend/storage/lmgr/lwlock.c

@@ -81,9 +81,6 @@
 #include "pgstat.h"
 #include "port/pg_bitutils.h"
 #include "postmaster/postmaster.h"
-#include "replication/slot.h"
-#include "storage/ipc.h"
-#include "storage/predicate.h"
 #include "storage/proc.h"
 #include "storage/proclist.h"
 #include "storage/spin.h"

src/backend/storage/lmgr/predicate.c

@@ -199,7 +199,6 @@
 
 #include "access/parallel.h"
 #include "access/slru.h"
-#include "access/subtrans.h"
 #include "access/transam.h"
 #include "access/twophase.h"
 #include "access/twophase_rmgr.h"
@@ -208,7 +207,6 @@
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "port/pg_lfind.h"
-#include "storage/bufmgr.h"
 #include "storage/predicate.h"
 #include "storage/predicate_internals.h"
 #include "storage/proc.h"

src/backend/storage/lmgr/proc.c

@@ -39,7 +39,6 @@
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "postmaster/autovacuum.h"
-#include "replication/slot.h"
 #include "replication/slotsync.h"
 #include "replication/syncrep.h"
 #include "storage/condition_variable.h"

src/backend/storage/lmgr/spin.c

@@ -23,7 +23,6 @@
 #include "postgres.h"
 
 #include "storage/pg_sema.h"
-#include "storage/shmem.h"
 #include "storage/spin.h"
 
 

src/backend/storage/smgr/md.c

@@ -25,21 +25,18 @@
 #include <fcntl.h>
 #include <sys/file.h>
 
-#include "access/xlog.h"
 #include "access/xlogutils.h"
 #include "commands/tablespace.h"
 #include "common/file_utils.h"
 #include "miscadmin.h"
 #include "pg_trace.h"
 #include "pgstat.h"
-#include "postmaster/bgwriter.h"
 #include "storage/bufmgr.h"
 #include "storage/fd.h"
 #include "storage/md.h"
 #include "storage/relfilelocator.h"
 #include "storage/smgr.h"
 #include "storage/sync.h"
-#include "utils/hsearch.h"
 #include "utils/memutils.h"
 
 /*

src/backend/storage/smgr/smgr.c

@@ -54,7 +54,6 @@
 #include "access/xlogutils.h"
 #include "lib/ilist.h"
 #include "storage/bufmgr.h"
-#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/md.h"
 #include "storage/smgr.h"

src/backend/storage/sync/sync.c

@@ -22,19 +22,14 @@
 #include "access/clog.h"
 #include "access/multixact.h"
 #include "access/xlog.h"
-#include "access/xlogutils.h"
-#include "commands/tablespace.h"
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "portability/instr_time.h"
 #include "postmaster/bgwriter.h"
-#include "storage/bufmgr.h"
 #include "storage/fd.h"
-#include "storage/ipc.h"
 #include "storage/latch.h"
 #include "storage/md.h"
 #include "utils/hsearch.h"
-#include "utils/inval.h"
 #include "utils/memutils.h"
 
 /*