BUG #16823: Unreachable code

The following bug has been logged on the website:

Bug reference:      16823
Logged by:          Rupert
Email address:      ruga@protonmail.com
PostgreSQL version: 13.1
Operating system:   openbsd
Description:

localtime.c:135:40: warning: code will never be executed
[-Wunreachable-code]
                result -= !TWOS_COMPLEMENT(int32) && result != 0;
                                                     ^~~~~~
localtime.c:161:40: warning: code will never be executed
[-Wunreachable-code]
                result -= !TWOS_COMPLEMENT(int64) && result != 0;
                                                     ^~~~~~
localtime.c:299:52: warning: code will never be executed
[-Wunreachable-code]
                                = ((TYPE_SIGNED(pg_time_t) ? at < TIME_T_MIN
: at < 0)

  ^~
localtime.c:1564:58: warning: code will never be executed
[-Wunreachable-code]
                  ? (TYPE_SIGNED(pg_time_t) ? TIME_T_MIN - j <= *tp : -1 - j
< *tp)
                                                                       ^
4 warnings generated.
bootparse.c:2132:14: warning: code will never be executed
[-Wunreachable-code]
  yyresult = 2;
             ^
1 warning generated.
bootstrap.c:465:4: warning: code will never be executed
[-Wunreachable-code]
                        proc_exit(1);           /* should never return */
                        ^~~~~~~~~
bootstrap.c:460:4: warning: code will never be executed
[-Wunreachable-code]
                        proc_exit(1);           /* should never return */
                        ^~~~~~~~~
bootstrap.c:454:4: warning: code will never be executed
[-Wunreachable-code]
                        proc_exit(1);           /* should never return */
                        ^~~~~~~~~
bootstrap.c:449:4: warning: code will never be executed
[-Wunreachable-code]
                        proc_exit(1);           /* should never return */
                        ^~~~~~~~~
bootstrap.c:444:4: warning: code will never be executed
[-Wunreachable-code]
                        proc_exit(1);           /* should never return */
                        ^~~~~~~~~
5 warnings generated.
main.c:211:2: warning: code will never be executed [-Wunreachable-code]
        abort();                                        /* should not get
here */
        ^~~~~
1 warning generated.
heapam.c:5364:11: warning: code will never be executed
[-Wunreachable-code]
        result = TM_Ok;
                 ^~~~~
1 warning generated.
postmaster.c:1419:2: warning: code will never be executed
[-Wunreachable-code]
        abort();                                        /* not reached */
        ^~~~~
postmaster.c:5513:3: warning: code will never be executed
[-Wunreachable-code]
                ExitPostmaster(0);
                ^~~~~~~~~~~~~~
postmaster.c:5892:4: warning: code will never be executed
[-Wunreachable-code]
                        exit(1);                        /* should not get
here */
                        ^~~~
3 warnings generated.
repl_gram.c:1942:14: warning: code will never be executed
[-Wunreachable-code]
  yyresult = 2;
             ^
1 warning generated.
scan.c:6678:13: warning: code will never be executed [-Wunreachable-code]
                                        if ( !
yyg->yy_did_buffer_switch_on_eof )
                                               ^~~
walsender.c:368:2: warning: code will never be executed
[-Wunreachable-code]
        abort();                                        /* keep the compiler
quiet */
        ^~~~~
1 warning generated.
1 warning generated.
ri_triggers.c:1554:3: warning: code will never be executed
[-Wunreachable-code]
                ExecDropSingleTupleTableSlot(slot);
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
fe-connect.c:1112:16: warning: code will never be executed
[-Wunreachable-code]
                                ch->host = strdup(DefaultHost);
                                           ^~~~~~
1 warning generated.
pgc.c:3825:14: warning: code will never be executed [-Wunreachable-code]
                                        if ( ! (yy_did_buffer_switch_on_eof)
)

^~~~~~~~~~~~~~~~~~~~~~~~~~~
variable.c:472:4: warning: code will never be executed
[-Wunreachable-code]
                        struct ECPGstruct_member *p;
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
data.c:372:6: warning: code will never be executed [-Wunreachable-code]
                                        long            res;
                                        ^~~~~~~~~~~~~~~~~~~~
execute.c:567:5: warning: code will never be executed [-Wunreachable-code]
                                int                     element;
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
1 warning generated.
1 warning generated.
psqlscan.c:3387:13: warning: code will never be executed
[-Wunreachable-code]
                                        if ( !
yyg->yy_did_buffer_switch_on_eof )
                                               ^~~
1 warning generated.
localtime.c:135:40: warning: code will never be executed
[-Wunreachable-code]
                result -= !TWOS_COMPLEMENT(int32) && result != 0;
                                                     ^~~~~~
localtime.c:161:40: warning: code will never be executed
[-Wunreachable-code]
                result -= !TWOS_COMPLEMENT(int64) && result != 0;
                                                     ^~~~~~
localtime.c:299:52: warning: code will never be executed
[-Wunreachable-code]
                                = ((TYPE_SIGNED(pg_time_t) ? at < TIME_T_MIN
: at < 0)

  ^~
localtime.c:1564:58: warning: code will never be executed
[-Wunreachable-code]
                  ? (TYPE_SIGNED(pg_time_t) ? TIME_T_MIN - j <= *tp : -1 - j
< *tp)
                                                                       ^
4 warnings generated.
file.c:355:2: warning: code will never be executed [-Wunreachable-code]
        unlink(new_link_file);
        ^~~~~~
1 warning generated.
exprparse.c:1869:14: warning: code will never be executed
[-Wunreachable-code]
  yyresult = 2;
             ^
1 warning generated.
psqlscanslash.c:2105:13: warning: code will never be executed
[-Wunreachable-code]
                                        if ( !
yyg->yy_did_buffer_switch_on_eof )
                                               ^~~
1 warning generated.
pl_gram.c:4924:14: warning: code will never be executed
[-Wunreachable-code]
  yyresult = 2;
             ^
1 warning generated.