pgsql: Split some long Makefile lists

Split some long Makefile lists

This change makes more readable code diffs when adding new items or
removing old items, while ensuring that lines do not get excessively
long. Some SUBDIRS, PROGRAMS and REGRESS lists are split.

Note that there are a few more REGRESS lists that could be split,
particularly in contrib/.

Author: Jelte Fennema-Nio <postgres(at)jeltef(dot)nl>
Co-Authored-By: Jacob Champion <jacob(dot)champion(at)enterprisedb(dot)com>
Reviewed-by: Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com>
Reviewed-by: Japin Li <japinli(at)hotmail(dot)com>
Reviewed-by: Man Zeng <zengman(at)halodbtech(dot)com>
Discussion: https://postgr.es/m/DF6HDGB559U5.3MPRFCWPONEAE@jeltef.nl

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/9adf32da6b48e423e632ac24d6c634021e1ab154

Modified Files
--------------
contrib/pageinspect/Makefile | 11 +++++++++-
src/backend/Makefile | 32 +++++++++++++++++++++++-----
src/backend/access/Makefile | 17 +++++++++++++--
src/backend/optimizer/Makefile | 7 +++++-
src/backend/storage/Makefile | 12 ++++++++++-
src/bin/scripts/Makefile | 10 ++++++++-
src/include/Makefile | 48 +++++++++++++++++++++++++++++++++++-------
src/interfaces/ecpg/Makefile | 7 +++++-
src/pl/tcl/Makefile | 12 ++++++++++-
src/test/Makefile | 10 ++++++++-
src/test/examples/Makefile | 8 ++++++-
11 files changed, 151 insertions(+), 23 deletions(-)