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/optimizer/geqo/geqo_cx.c

@@ -35,11 +35,13 @@
 
 
 #include "postgres.h"
-#include "optimizer/geqo_random.h"
-#include "optimizer/geqo_recombination.h"
+#include "optimizer/geqo.h"
 
 #if defined(CX)
 
+#include "optimizer/geqo_random.h"
+#include "optimizer/geqo_recombination.h"
+
 /* cx
  *
  *	 cycle crossover

src/backend/optimizer/geqo/geqo_erx.c

@@ -32,11 +32,13 @@
 
 
 #include "postgres.h"
-#include "optimizer/geqo_random.h"
-#include "optimizer/geqo_recombination.h"
+#include "optimizer/geqo.h"
 
 #if defined(ERX)
 
+#include "optimizer/geqo_random.h"
+#include "optimizer/geqo_recombination.h"
+
 static int	gimme_edge(PlannerInfo *root, Gene gene1, Gene gene2, Edge *edge_table);
 static void remove_gene(PlannerInfo *root, Gene gene, Edge edge, Edge *edge_table);
 static Gene gimme_gene(PlannerInfo *root, Edge edge, Edge *edge_table);

src/backend/optimizer/geqo/geqo_main.c

@@ -26,10 +26,15 @@
 
 #include <math.h>
 
+#include "optimizer/geqo.h"
+
 #include "optimizer/geqo_misc.h"
+#if defined(CX)
 #include "optimizer/geqo_mutation.h"
+#endif
 #include "optimizer/geqo_pool.h"
 #include "optimizer/geqo_random.h"
+#include "optimizer/geqo_recombination.h"
 #include "optimizer/geqo_selection.h"
 
 

src/backend/optimizer/geqo/geqo_mutation.c

@@ -32,11 +32,13 @@
 /*************************************************************/
 
 #include "postgres.h"
-#include "optimizer/geqo_mutation.h"
-#include "optimizer/geqo_random.h"
+#include "optimizer/geqo.h"
 
 #if defined(CX)					/* currently used only in CX mode */
 
+#include "optimizer/geqo_mutation.h"
+#include "optimizer/geqo_random.h"
+
 void
 geqo_mutation(PlannerInfo *root, Gene *tour, int num_gene)
 {

src/backend/optimizer/geqo/geqo_ox1.c

@@ -34,11 +34,13 @@
 /*************************************************************/
 
 #include "postgres.h"
-#include "optimizer/geqo_random.h"
-#include "optimizer/geqo_recombination.h"
+#include "optimizer/geqo.h"
 
 #if defined(OX1)
 
+#include "optimizer/geqo_random.h"
+#include "optimizer/geqo_recombination.h"
+
 /* ox1
  *
  *	 position crossover

src/backend/optimizer/geqo/geqo_ox2.c

@@ -34,11 +34,13 @@
 /*************************************************************/
 
 #include "postgres.h"
-#include "optimizer/geqo_random.h"
-#include "optimizer/geqo_recombination.h"
+#include "optimizer/geqo.h"
 
 #if defined(OX2)
 
+#include "optimizer/geqo_random.h"
+#include "optimizer/geqo_recombination.h"
+
 /* ox2
  *
  *	 position crossover

src/backend/optimizer/geqo/geqo_pmx.c

@@ -34,11 +34,13 @@
 /*************************************************************/
 
 #include "postgres.h"
-#include "optimizer/geqo_random.h"
-#include "optimizer/geqo_recombination.h"
+#include "optimizer/geqo.h"
 
 #if defined(PMX)
 
+#include "optimizer/geqo_random.h"
+#include "optimizer/geqo_recombination.h"
+
 /* pmx
  *
  *	 partially matched crossover

src/backend/optimizer/geqo/geqo_px.c

@@ -34,11 +34,13 @@
 /*************************************************************/
 
 #include "postgres.h"
-#include "optimizer/geqo_random.h"
-#include "optimizer/geqo_recombination.h"
+#include "optimizer/geqo.h"
 
 #if defined(PX)
 
+#include "optimizer/geqo_random.h"
+#include "optimizer/geqo_recombination.h"
+
 /* px
  *
  *	 position crossover

src/backend/optimizer/path/allpaths.c

@@ -35,18 +35,15 @@
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
 #include "optimizer/geqo.h"
-#include "optimizer/inherit.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/plancat.h"
 #include "optimizer/planner.h"
-#include "optimizer/restrictinfo.h"
 #include "optimizer/tlist.h"
 #include "parser/parse_clause.h"
 #include "parser/parsetree.h"
 #include "partitioning/partbounds.h"
-#include "partitioning/partprune.h"
 #include "port/pg_bitutils.h"
 #include "rewrite/rewriteManip.h"
 #include "utils/lsyscache.h"

src/backend/optimizer/path/clausesel.c

@@ -14,10 +14,8 @@
  */
 #include "postgres.h"
 
-#include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/clauses.h"
-#include "optimizer/cost.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/plancat.h"

src/backend/optimizer/path/costsize.c

@@ -91,7 +91,6 @@
 #include "optimizer/paths.h"
 #include "optimizer/placeholder.h"
 #include "optimizer/plancat.h"
-#include "optimizer/planmain.h"
 #include "optimizer/restrictinfo.h"
 #include "parser/parsetree.h"
 #include "utils/lsyscache.h"

src/backend/optimizer/path/pathkeys.c

@@ -19,9 +19,7 @@
 
 #include "access/stratnum.h"
 #include "catalog/pg_opfamily.h"
-#include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
-#include "nodes/plannodes.h"
 #include "optimizer/cost.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"

src/backend/optimizer/path/tidpath.c

@@ -42,7 +42,6 @@
 #include "catalog/pg_operator.h"
 #include "catalog/pg_type.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"

src/backend/optimizer/plan/analyzejoins.c

@@ -24,14 +24,12 @@
 
 #include "catalog/pg_class.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
 #include "optimizer/joininfo.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/planmain.h"
 #include "optimizer/restrictinfo.h"
-#include "optimizer/tlist.h"
 #include "utils/lsyscache.h"
 
 /*

src/backend/optimizer/plan/initsplan.c

@@ -14,7 +14,6 @@
  */
 #include "postgres.h"
 
-#include "catalog/pg_class.h"
 #include "catalog/pg_type.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
@@ -28,7 +27,6 @@
 #include "optimizer/placeholder.h"
 #include "optimizer/planmain.h"
 #include "optimizer/planner.h"
-#include "optimizer/prep.h"
 #include "optimizer/restrictinfo.h"
 #include "parser/analyze.h"
 #include "rewrite/rewriteManip.h"

src/backend/optimizer/plan/planagg.c

@@ -33,7 +33,6 @@
 #include "catalog/pg_type.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
 #include "optimizer/cost.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/pathnode.h"

src/backend/optimizer/plan/planmain.c

@@ -22,7 +22,6 @@
 
 #include "optimizer/appendinfo.h"
 #include "optimizer/clauses.h"
-#include "optimizer/inherit.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/orclauses.h"
 #include "optimizer/pathnode.h"

src/backend/optimizer/plan/planner.c

@@ -19,18 +19,15 @@
 #include <math.h>
 
 #include "access/genam.h"
-#include "access/htup_details.h"
 #include "access/parallel.h"
 #include "access/sysattr.h"
 #include "access/table.h"
-#include "access/xact.h"
 #include "catalog/pg_aggregate.h"
 #include "catalog/pg_constraint.h"
 #include "catalog/pg_inherits.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "executor/executor.h"
-#include "executor/nodeAgg.h"
 #include "foreign/fdwapi.h"
 #include "jit/jit.h"
 #include "lib/bipartite_match.h"
@@ -45,7 +42,6 @@
 #include "optimizer/appendinfo.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
-#include "optimizer/inherit.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/paramassign.h"
 #include "optimizer/pathnode.h"
@@ -61,12 +57,9 @@
 #include "parser/parse_relation.h"
 #include "parser/parsetree.h"
 #include "partitioning/partdesc.h"
-#include "rewrite/rewriteManip.h"
-#include "storage/dsm_impl.h"
 #include "utils/lsyscache.h"
 #include "utils/rel.h"
 #include "utils/selfuncs.h"
-#include "utils/syscache.h"
 
 /* GUC parameters */
 double		cursor_tuple_fraction = DEFAULT_CURSOR_TUPLE_FRACTION;

src/backend/optimizer/plan/setrefs.c

@@ -27,7 +27,6 @@
 #include "optimizer/tlist.h"
 #include "parser/parse_relation.h"
 #include "tcop/utility.h"
-#include "utils/lsyscache.h"
 #include "utils/syscache.h"
 
 

src/backend/optimizer/prep/prepagg.c

@@ -39,7 +39,6 @@
 #include "catalog/pg_type.h"
 #include "nodes/nodeFuncs.h"
 #include "nodes/pathnodes.h"
-#include "optimizer/clauses.h"
 #include "optimizer/cost.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/plancat.h"

src/backend/optimizer/prep/prepqual.c

@@ -34,7 +34,6 @@
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "optimizer/optimizer.h"
-#include "optimizer/prep.h"
 #include "utils/lsyscache.h"
 
 

src/backend/optimizer/prep/prepunion.c

@@ -24,9 +24,6 @@
 #include "postgres.h"
 
 #include "access/htup_details.h"
-#include "access/sysattr.h"
-#include "catalog/partition.h"
-#include "catalog/pg_inherits.h"
 #include "catalog/pg_type.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
@@ -34,16 +31,11 @@
 #include "optimizer/cost.h"
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
-#include "optimizer/planmain.h"
 #include "optimizer/planner.h"
 #include "optimizer/prep.h"
 #include "optimizer/tlist.h"
 #include "parser/parse_coerce.h"
-#include "parser/parsetree.h"
-#include "utils/lsyscache.h"
-#include "utils/rel.h"
 #include "utils/selfuncs.h"
-#include "utils/syscache.h"
 
 
 static RelOptInfo *recurse_set_operations(Node *setOp, PlannerInfo *root,

src/backend/optimizer/util/clauses.c

@@ -20,8 +20,6 @@
 #include "postgres.h"
 
 #include "access/htup_details.h"
-#include "catalog/pg_aggregate.h"
-#include "catalog/pg_class.h"
 #include "catalog/pg_language.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_proc.h"
@@ -41,7 +39,6 @@
 #include "optimizer/plancat.h"
 #include "optimizer/planmain.h"
 #include "parser/analyze.h"
-#include "parser/parse_agg.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_func.h"
 #include "rewrite/rewriteHandler.h"

src/backend/optimizer/util/orclauses.c

@@ -17,8 +17,6 @@
 
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
-#include "optimizer/clauses.h"
-#include "optimizer/cost.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/orclauses.h"
 #include "optimizer/restrictinfo.h"

src/backend/optimizer/util/pathnode.c

@@ -19,7 +19,6 @@
 #include "foreign/fdwapi.h"
 #include "miscadmin.h"
 #include "nodes/extensible.h"
-#include "nodes/nodeFuncs.h"
 #include "optimizer/appendinfo.h"
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
@@ -27,11 +26,8 @@
 #include "optimizer/pathnode.h"
 #include "optimizer/paths.h"
 #include "optimizer/planmain.h"
-#include "optimizer/prep.h"
-#include "optimizer/restrictinfo.h"
 #include "optimizer/tlist.h"
 #include "parser/parsetree.h"
-#include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/selfuncs.h"
 

src/backend/optimizer/util/plancat.c

@@ -36,11 +36,9 @@
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
 #include "nodes/supportnodes.h"
-#include "optimizer/clauses.h"
 #include "optimizer/cost.h"
 #include "optimizer/optimizer.h"
 #include "optimizer/plancat.h"
-#include "optimizer/prep.h"
 #include "parser/parse_relation.h"
 #include "parser/parsetree.h"
 #include "partitioning/partdesc.h"