Add some noreturn attributes based on compiler recommendations

contrib/test_shm_mq/test_shm_mq.h

@@ -40,6 +40,6 @@ extern void test_shm_mq_setup(int64 queue_size, int32 nworkers,
 				  shm_mq_handle **input);
 
 /* Main entrypoint for a worker. */
-extern void test_shm_mq_main(Datum);
+extern void test_shm_mq_main(Datum) __attribute__((noreturn));
 
 #endif

contrib/worker_spi/worker_spi.c

@@ -46,7 +46,7 @@ PG_MODULE_MAGIC;
 PG_FUNCTION_INFO_V1(worker_spi_launch);
 
 void		_PG_init(void);
-void		worker_spi_main(Datum);
+void		worker_spi_main(Datum) __attribute__((noreturn));
 
 /* flags set by signal handlers */
 static volatile sig_atomic_t got_sighup = false;

src/include/bootstrap/bootstrap.h

@@ -57,6 +57,6 @@ extern void boot_get_type_io_data(Oid typid,
 extern int	boot_yyparse(void);
 
 extern int	boot_yylex(void);
-extern void boot_yyerror(const char *str);
+extern void boot_yyerror(const char *str) __attribute__((noreturn));
 
 #endif   /* BOOTSTRAP_H */

src/include/parser/scanner.h

@@ -114,6 +114,6 @@ extern void scanner_finish(core_yyscan_t yyscanner);
 extern int core_yylex(core_YYSTYPE *lvalp, YYLTYPE *llocp,
 		   core_yyscan_t yyscanner);
 extern int	scanner_errposition(int location, core_yyscan_t yyscanner);
-extern void scanner_yyerror(const char *message, core_yyscan_t yyscanner);
+extern void scanner_yyerror(const char *message, core_yyscan_t yyscanner) __attribute__((noreturn));
 
 #endif   /* SCANNER_H */

src/include/postmaster/bgworker_internals.h

@@ -46,7 +46,7 @@ extern void BackgroundWorkerStopNotifications(pid_t pid);
 extern void ResetBackgroundWorkerCrashTimes(void);
 
 /* Function to start a background worker, called from postmaster.c */
-extern void StartBackgroundWorker(void);
+extern void StartBackgroundWorker(void) __attribute__((noreturn));
 
 #ifdef EXEC_BACKEND
 extern BackgroundWorker *BackgroundWorkerEntry(int slotno);