pgsql: Remove #include <math.h> where not needed

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(at)qq(dot)com>
Co-authored-by: Álvaro Herrera <alvherre(at)kurilemu(dot)de>
Discussion: https://postgr.es/m/tencent_6B302BFCAF6F010E00AB5C2C0ECB7AA3F205@qq.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/35e3fae738e63f4154814dd51d3806d8d8b7b673

Modified Files
--------------
contrib/btree_gist/btree_numeric.c | 1 -
contrib/btree_gist/btree_utils_var.c | 1 -
contrib/intarray/_intbig_gist.c | 2 --
contrib/ltree/_ltree_gist.c | 2 --
src/backend/access/heap/vacuumlazy.c | 2 --
src/backend/access/transam/xlogrecovery.c | 1 -
src/backend/access/transam/xlogwait.c | 1 -
src/backend/commands/define.c | 1 -
src/backend/executor/nodeBitmapHeapscan.c | 2 --
src/backend/executor/nodeSubplan.c | 2 --
src/backend/lib/knapsack.c | 1 -
src/backend/nodes/readfuncs.c | 2 --
src/backend/optimizer/geqo/geqo_eval.c | 1 -
src/backend/optimizer/geqo/geqo_pool.c | 1 -
src/backend/optimizer/path/indxpath.c | 2 --
src/backend/optimizer/path/joinpath.c | 2 --
src/backend/optimizer/plan/createplan.c | 2 --
src/backend/optimizer/util/pathnode.c | 2 --
src/backend/statistics/mcv.c | 2 --
src/backend/utils/adt/numutils.c | 1 -
src/backend/utils/adt/tid.c | 1 -
src/common/binaryheap.c | 2 --
src/include/utils/date.h | 2 --
23 files changed, 36 deletions(-)