Remove #include <math.h> where not needed

Liujinyang reported the one in binaryheap.c, I then found and analyzed
the rest.

For future patches, we require git archaelogical analysis before we
accept patches of this nature.

Co-authored-by: liujinyang <21043272@qq.com>
Co-authored-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/tencent_6B302BFCAF6F010E00AB5C2C0ECB7AA3F205@qq.com

contrib/btree_gist/btree_numeric.c

@@ -3,7 +3,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
 #include <float.h>
 
 #include "btree_gist.h"

contrib/btree_gist/btree_utils_var.c

@@ -3,7 +3,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
 #include <limits.h>
 #include <float.h>
 

contrib/intarray/_intbig_gist.c

@@ -3,8 +3,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "_int.h"
 #include "access/gist.h"
 #include "access/reloptions.h"

contrib/ltree/_ltree_gist.c

@@ -7,8 +7,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/gist.h"
 #include "access/reloptions.h"
 #include "access/stratnum.h"

src/backend/access/heap/vacuumlazy.c

@@ -129,8 +129,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/genam.h"
 #include "access/heapam.h"
 #include "access/htup_details.h"

src/backend/access/transam/xlogrecovery.c

@@ -25,7 +25,6 @@
 #include "postgres.h"
 
 #include <ctype.h>
-#include <math.h>
 #include <time.h>
 #include <sys/stat.h>
 #include <sys/time.h>

src/backend/access/transam/xlogwait.c

@@ -47,7 +47,6 @@
 #include "postgres.h"
 
 #include <float.h>
-#include <math.h>
 
 #include "access/xlog.h"
 #include "access/xlogrecovery.h"

src/backend/commands/define.c

@@ -20,7 +20,6 @@
 #include "postgres.h"
 
 #include <ctype.h>
-#include <math.h>
 
 #include "catalog/namespace.h"
 #include "commands/defrem.h"

src/backend/executor/nodeBitmapHeapscan.c

@@ -35,8 +35,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/relscan.h"
 #include "access/tableam.h"
 #include "access/visibilitymap.h"

src/backend/executor/nodeSubplan.c

@@ -26,8 +26,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/htup_details.h"
 #include "executor/executor.h"
 #include "executor/nodeSubplan.h"

src/backend/lib/knapsack.c

@@ -24,7 +24,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
 #include <limits.h>
 
 #include "lib/knapsack.h"

src/backend/nodes/readfuncs.c

@@ -26,8 +26,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "miscadmin.h"
 #include "nodes/bitmapset.h"
 #include "nodes/readfuncs.h"

src/backend/optimizer/geqo/geqo_eval.c

@@ -23,7 +23,6 @@
 
 #include <float.h>
 #include <limits.h>
-#include <math.h>
 
 #include "optimizer/geqo.h"
 #include "optimizer/joininfo.h"

src/backend/optimizer/geqo/geqo_pool.c

@@ -25,7 +25,6 @@
 
 #include <float.h>
 #include <limits.h>
-#include <math.h>
 
 #include "optimizer/geqo_copy.h"
 #include "optimizer/geqo_pool.h"

src/backend/optimizer/path/indxpath.c

@@ -15,8 +15,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/stratnum.h"
 #include "access/sysattr.h"
 #include "access/transam.h"

src/backend/optimizer/path/joinpath.c

@@ -14,8 +14,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "executor/executor.h"
 #include "foreign/fdwapi.h"
 #include "nodes/nodeFuncs.h"

src/backend/optimizer/plan/createplan.c

@@ -16,8 +16,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/sysattr.h"
 #include "catalog/pg_class.h"
 #include "foreign/fdwapi.h"

src/backend/optimizer/util/pathnode.c

@@ -14,8 +14,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/htup_details.h"
 #include "executor/nodeSetOp.h"
 #include "foreign/fdwapi.h"

src/backend/statistics/mcv.c

@@ -14,8 +14,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
-
 #include "access/htup_details.h"
 #include "catalog/pg_statistic_ext.h"
 #include "catalog/pg_statistic_ext_data.h"

src/backend/utils/adt/numutils.c

@@ -14,7 +14,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
 #include <limits.h>
 #include <ctype.h>
 

src/backend/utils/adt/tid.c

@@ -17,7 +17,6 @@
  */
 #include "postgres.h"
 
-#include <math.h>
 #include <limits.h>
 
 #include "access/sysattr.h"

src/common/binaryheap.c

@@ -17,8 +17,6 @@
 #include "postgres.h"
 #endif
 
-#include <math.h>
-
 #ifdef FRONTEND
 #include "common/logging.h"
 #endif

src/include/utils/date.h

@@ -14,8 +14,6 @@
 #ifndef DATE_H
 #define DATE_H
 
-#include <math.h>
-
 #include "datatype/timestamp.h"
 #include "fmgr.h"
 #include "pgtime.h"