Add missing includes for some global variables

src/backend/libpq/pqcomm.c: "postmaster/postmaster.h" for Unix_socket_group, Unix_socket_permissions
src/backend/utils/init/globals.c: "postmaster/postmaster.h" for MyClientSocket
src/backend/utils/misc/guc_tables.c: "utils/rls.h" for row_security
src/backend/utils/sort/tuplesort.c: "utils/guc.h" for trace_sort

Nothing currently diagnoses missing includes for global variables, but
this is being cleaned up, and these ones had an obvious header file
available.

Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/flat/e0a62134-83da-4ba4-8cdb-ceb0111c95ce@eisentraut.org

src/backend/libpq/pqcomm.c

@@ -76,6 +76,7 @@
 #include "libpq/libpq.h"
 #include "miscadmin.h"
 #include "port/pg_bswap.h"
+#include "postmaster/postmaster.h"
 #include "storage/ipc.h"
 #include "utils/guc_hooks.h"
 #include "utils/memutils.h"

src/backend/utils/init/globals.c

@@ -22,6 +22,7 @@
 #include "libpq/libpq-be.h"
 #include "libpq/pqcomm.h"
 #include "miscadmin.h"
+#include "postmaster/postmaster.h"
 #include "storage/procnumber.h"
 
 

src/backend/utils/misc/guc_tables.c

@@ -87,6 +87,7 @@
 #include "utils/pg_locale.h"
 #include "utils/plancache.h"
 #include "utils/ps_status.h"
+#include "utils/rls.h"
 #include "utils/xml.h"
 
 /* This value is normally passed in from the Makefile */

src/backend/utils/sort/tuplesort.c

@@ -105,6 +105,7 @@
 #include "miscadmin.h"
 #include "pg_trace.h"
 #include "storage/shmem.h"
+#include "utils/guc.h"
 #include "utils/memutils.h"
 #include "utils/pg_rusage.h"
 #include "utils/tuplesort.h"