pgsql: Refactor ParamListInfo initialization

Refactor ParamListInfo initialization

There were six copies of identical nontrivial code. Put it into a
function.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/c6ff0b892c30122b75d32c524109d16ee3c973f0

Modified Files
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src/backend/commands/prepare.c | 12 +-------
src/backend/executor/functions.c | 15 ++--------
src/backend/executor/spi.c | 17 ++----------
src/backend/nodes/params.c | 59 +++++++++++++++++++++-------------------
src/backend/tcop/postgres.c | 11 +-------
src/include/nodes/params.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
7 files changed, 40 insertions(+), 78 deletions(-)