pgsql: Remove SHM_QUEUE

Remove SHM_QUEUE

Prior patches got rid of all the uses of SHM_QUEUE. ilist.h style lists are
more widely used and have an easier to use interface. As there are no users
left, remove SHM_QUEUE.

Reviewed-by: Thomas Munro <thomas.munro@gmail.com> (in an older version)
Discussion: https://postgr.es/m/20221120055930.t6kl3tyivzhlrzu2@awork3.anarazel.de
Discussion: https://postgr.es/m/20200211042229.msv23badgqljrdg2@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/d137cb52cb7fd44a3f24f3c750fbf7924a4e9532

Modified Files
--------------
src/backend/storage/ipc/Makefile    |   1 -
src/backend/storage/ipc/meson.build |   1 -
src/backend/storage/ipc/shmqueue.c  | 190 ------------------------------------
src/include/storage/shmem.h         |  22 -----
src/tools/pgindent/typedefs.list    |   1 -
5 files changed, 215 deletions(-)