Standardize spelling of "nonblocking"

Only adjusted the user-exposed messages and documentation,  not all
source code comments.

doc/src/sgml/indexam.sgml

@@ -746,7 +746,7 @@ amrestrpos (IndexScanDesc scan);
   <para>
    When the <structfield>ampredlocks</> flag is not set, any scan using that
    index access method within a serializable transaction will acquire a
-   non-blocking predicate lock on the full index.  This will generate a
+   nonblocking predicate lock on the full index.  This will generate a
    read-write conflict with the insert of any tuple into that index by a
    concurrent serializable transaction.  If certain patterns of read-write
    conflicts are detected among a set of concurrent serializable

doc/src/sgml/mvcc.sgml

@@ -1366,7 +1366,7 @@ SELECT pg_advisory_lock(q.id) FROM
    <para>
     As mentioned in <xref linkend="xact-serializable">, Serializable
     transactions are just Repeatable Read transactions which add
-    non-blocking monitoring for dangerous patterns of read/write conflicts.
+    nonblocking monitoring for dangerous patterns of read/write conflicts.
     When a pattern is detected which could cause a cycle in the apparent
     order of execution, one of the transactions involved is rolled back to
     break the cycle.

src/backend/libpq/pqcomm.c

@@ -808,7 +808,7 @@ pq_set_nonblocking(bool nonblocking)
 	{
 		if (!pg_set_noblock(MyProcPort->sock))
 			ereport(COMMERROR,
-				  (errmsg("could not set socket to non-blocking mode: %m")));
+				  (errmsg("could not set socket to nonblocking mode: %m")));
 	}
 	else
 	{

src/backend/postmaster/postmaster.c

@@ -6261,7 +6261,7 @@ InitPostmasterDeathWatchHandle(void)
 	if (fcntl(postmaster_alive_fds[POSTMASTER_FD_WATCH], F_SETFL, O_NONBLOCK))
 		ereport(FATAL,
 				(errcode_for_socket_access(),
-				 errmsg_internal("could not set postmaster death monitoring pipe to non-blocking mode: %m")));
+				 errmsg_internal("could not set postmaster death monitoring pipe to nonblocking mode: %m")));
 #else
 
 	/*

src/interfaces/libpq/fe-auth.c

@@ -285,7 +285,7 @@ pg_krb5_sendauth(PGconn *conn)
 		char		sebuf[256];
 
 		printfPQExpBuffer(&conn->errorMessage,
-		libpq_gettext("could not restore non-blocking mode on socket: %s\n"),
+		libpq_gettext("could not restore nonblocking mode on socket: %s\n"),
 						  pqStrerror(errno, sebuf, sizeof(sebuf)));
 		ret = STATUS_ERROR;
 	}

src/interfaces/libpq/fe-connect.c

@@ -1666,7 +1666,7 @@ keep_going:						/* We will come back to here until there is
 					if (!pg_set_noblock(conn->sock))
 					{
 						appendPQExpBuffer(&conn->errorMessage,
-										  libpq_gettext("could not set socket to non-blocking mode: %s\n"),
+										  libpq_gettext("could not set socket to nonblocking mode: %s\n"),
 							SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
 						pqDropConnection(conn);
 						conn->addr_cur = addr_cur->ai_next;