Mark some more functions as pg_attribute_noreturn().

Doing this suppresses Coverity warnings and might allow improved
code in some cases.  The prospects of that are not so bright as
to warrant back-patching, though.

Michael Paquier, per Coverity

src/bin/initdb/initdb.c

@@ -237,7 +237,7 @@ static char **filter_lines_with_token(char **lines, const char *token);
 static char **readfile(const char *path);
 static void writefile(char *path, char **lines);
 static FILE *popen_check(const char *command, const char *mode);
-static void exit_nicely(void);
+static void exit_nicely(void) pg_attribute_noreturn();
 static char *get_id(void);
 static int get_encoding_id(const char *encoding_name);
 static void set_input(char **dest, const char *filename);

src/bin/pg_basebackup/pg_basebackup.c

@@ -132,7 +132,7 @@ static PQExpBuffer recoveryconfcontents = NULL;
 
 /* Function headers */
 static void usage(void);
-static void disconnect_and_exit(int code);
+static void disconnect_and_exit(int code) pg_attribute_noreturn();
 static void verify_dir_is_empty_or_create(char *dirname, bool *created, bool *found);
 static void progress_report(int tablespacenum, const char *filename, bool force);
 

src/bin/pg_basebackup/pg_recvlogical.c

@@ -64,7 +64,7 @@ static XLogRecPtr output_fsync_lsn = InvalidXLogRecPtr;
 
 static void usage(void);
 static void StreamLogicalLog(void);
-static void disconnect_and_exit(int code);
+static void disconnect_and_exit(int code) pg_attribute_noreturn();
 static bool flushAndSendFeedback(PGconn *conn, TimestampTz *now);
 static void prepareToTerminate(PGconn *conn, XLogRecPtr endpos,
 				   bool keepalive, XLogRecPtr lsn);

src/test/isolation/isolationtester.c

@@ -32,6 +32,7 @@ static int	nconns = 0;
 /* In dry run only output permutations to be run by the tester. */
 static int	dry_run = false;
 
+static void exit_nicely(void) pg_attribute_noreturn();
 static void run_testspec(TestSpec *testspec);
 static void run_all_permutations(TestSpec *testspec);
 static void run_all_permutations_recurse(TestSpec *testspec, int nsteps,