pgsql: Use C99-designated initializer syntax for more arrays

Use C99-designated initializer syntax for more arrays

This is in the same spirit as ef5e2e90859a, updating this time some
arrays in parser.c, relpath.c, guc_tables.c and pg_dump_sort.c so as the
order of their elements has no need to match the enum structures they
are based on anymore.

Author: Jelte Fennema-Nio
Reviewed-by: Jian He, Japin Li
Discussion: https://postgr.es/m/CAGECzQT3caUbcCcszNewCCmMbCuyP7XNAm60J3ybd6PN5kH2Dw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/afd8ef39094b0dff9d1f2bfecb1d9fa056b85e19

Modified Files
--------------
src/backend/parser/parser.c         |  12 +--
src/backend/utils/misc/guc_tables.c | 187 ++++++++++++++----------------------
src/bin/pg_dump/pg_dump_sort.c      |  94 +++++++++---------
src/common/relpath.c                |   8 +-
4 files changed, 128 insertions(+), 173 deletions(-)