pgsql: Convert lwlock.c to use the new shmem allocation functions

Convert lwlock.c to use the new shmem allocation functions

It seems like a good candidate to convert first because it needs to
initialized before any other subsystem, but other than that it's
nothing special.

Reviewed-by: Ashutosh Bapat <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres(at)gmail(dot)com>
Reviewed-by: Daniel Gustafsson <daniel(at)yesql(dot)se>
Discussion: https://www.postgresql.org/message-id/CAExHW5vM1bneLYfg0wGeAa=52UiJ3z4vKd3AJ72X8Fw6k3KKrg@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a006bc7b1699d952afcb6d786343e8bf0ecc61d6

Modified Files
--------------
src/backend/postmaster/postmaster.c | 16 +++---
src/backend/storage/ipc/ipci.c | 13 -----
src/backend/storage/lmgr/lwlock.c | 100 +++++++++++++++++-------------------
src/backend/tcop/postgres.c | 16 +++---
src/include/storage/lwlock.h | 2 -
src/include/storage/subsystemlist.h | 9 +++-
6 files changed, 75 insertions(+), 81 deletions(-)