pgsql: Rationalize order of input files for gen_node_support.pl.

Rationalize order of input files for gen_node_support.pl.

Per a question from Andres Freund.  While here, also make the
list of nodetag-only files easier to compare to the full list
of input files.

Discussion: https://postgr.es/m/20220710214622.haiektrjzisob6rl@awork3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/bf022d337ef096c79e6a0b51f0b42e69749ae210

Modified Files
--------------
src/backend/nodes/Makefile            | 28 ++++++++++++++++------------
src/backend/nodes/gen_node_support.pl | 27 +++++++++++++++++++++------
src/tools/msvc/Solution.pm            | 27 +++++++++++++--------------
3 files changed, 50 insertions(+), 32 deletions(-)