pgsql: Remove more volatile qualifiers.

Remove more volatile qualifiers.

Prior to commit 0709b7ee72e4bc71ad07b7120acd117265ab51d0, access to
variables within a spinlock-protected critical section had to be done
through a volatile pointer, but that should no longer be necessary.
This continues work begun in df4077cda2eae3eb4a5cf387da0c1e7616e73204
and 6ba4ecbf477e0b25dd7bde1b0c4e07fc2da19348.

Thomas Munro and Michael Paquier

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/8f6bb851bdb75d741b3a7543bbf681e3cd7e65dc

Modified Files
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src/backend/postmaster/checkpointer.c      |   64 ++++++++----------
src/backend/replication/logical/logical.c  |   49 ++++++--------
src/backend/replication/slot.c             |  100 ++++++++++------------------
src/backend/replication/walreceiver.c      |   16 ++---
src/backend/replication/walreceiverfuncs.c |   22 ++----
src/backend/replication/walsender.c        |   39 ++++-------
6 files changed, 108 insertions(+), 182 deletions(-)