pgsql: Remove local optimizations of empty Bitmapsets into null pointer

Remove local optimizations of empty Bitmapsets into null pointers.

These are all dead code now that it's done centrally.

Patch by me; thanks to Nathan Bossart and Richard Guo for review.

Discussion: https://postgr.es/m/1159933.1677621588@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6b661b01f48bb0d3129ad0e3909210a6ba0534b3

Modified Files
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src/backend/executor/execUtils.c | 10 +---------
src/backend/optimizer/path/indxpath.c | 3 ---
src/backend/optimizer/plan/initsplan.c | 10 ++--------
src/backend/optimizer/plan/subselect.c | 9 ---------
src/backend/optimizer/util/pathnode.c | 6 ------
src/backend/optimizer/util/placeholder.c | 2 --
src/backend/optimizer/util/relnode.c | 7 -------
src/backend/rewrite/rewriteManip.c | 19 ++++---------------
src/pl/plpgsql/src/pl_exec.c | 7 ++-----
9 files changed, 9 insertions(+), 64 deletions(-)