pgsql: Quieten warnings about unused variables

Quieten warnings about unused variables

These variables are only ever written to in assertion-enabled builds,
and the latest Microsoft compilers complain about such variables in
non-assertion-enabled builds.

Apparently they don't worry so much about variables that are written to
but not read from, so most of our PG_USED_FOR_ASSERTS_ONLY variables
don't cause the problem.

Discussion: https://postgr.es/m/7800.1505950322@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/28ae524bbf865d23eb10f6ae1b996d59dcc30e4e

Modified Files
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src/backend/optimizer/path/costsize.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)