pgsql: Code review for commit b6e1157e7d

Code review for commit b6e1157e7d

b6e1157e7d made some changes to enforce that
JsonValueExpr.formatted_expr is always set and is the expression that
gives a JsonValueExpr its runtime value, but that's not really
apparent from the comments about and the code manipulating
formatted_expr.  This commit fixes that.

Per suggestion from Álvaro Herrera.

Discussion: https://postgr.es/m/20230718155313.3wqg6encgt32adqb%40alvherre.pgsql

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/7c7412cae3ea8f8accdec1022969a9360b74f253

Modified Files
--------------
src/backend/nodes/makefuncs.c   | 11 ++++-------
src/backend/nodes/nodeFuncs.c   |  4 +---
src/backend/parser/gram.y       |  4 +++-
src/backend/parser/parse_expr.c | 17 +++++++++++------
src/include/nodes/makefuncs.h   |  3 ++-
src/include/nodes/primnodes.h   |  5 +++--
6 files changed, 24 insertions(+), 20 deletions(-)