prel gcc14 doio.c:218:9: error: implicit declaration of function 'dup3'; did you mean 'dup2'? [-Wimplicit-function-declaration]

doio.c: In function 'Perl_PerlLIO_dup2_cloexec':
doio.c:218:9: error: implicit declaration of function 'dup3'; did you mean 'dup2'? [-Wimplicit-function-declaration]
218 | dup3(oldfd, newfd, O_CLOEXEC),
| ^~~~
doio.c:125:32: note: in definition of macro 'DO_GENOPEN_EXPERIMENTING_CLOEXEC'
125 | int res = (GENOPEN_CLOEXEC), eno;
| ^~~~~~~~~~~~~~~
doio.c:216:5: note: in expansion of macro 'DO_ONEOPEN_EXPERIMENTING_CLOEXEC'
216 | DO_ONEOPEN_EXPERIMENTING_CLOEXEC(
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
doio.c: In function 'Perl_my_mkstemp_cloexec':
util.h:273:45: error: implicit declaration of function 'mkostemp'; did you mean 'mkstemp'? [-Wimplicit-function-declaration]
273 | # define Perl_my_mkostemp(templte, flags) mkostemp(templte, flags)
| ^~~~~~~~
doio.c:125:32: note: in definition of macro 'DO_GENOPEN_EXPERIMENTING_CLOEXEC'
125 | int res = (GENOPEN_CLOEXEC), eno;
| ^~~~~~~~~~~~~~~
doio.c:336:5: note: in expansion of macro 'DO_ONEOPEN_EXPERIMENTING_CLOEXEC'
336 | DO_ONEOPEN_EXPERIMENTING_CLOEXEC(
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
doio.c:338:9: note: in expansion of macro 'Perl_my_mkostemp'
338 | Perl_my_mkostemp(templte, O_CLOEXEC),
| ^~~~~~~~~~~~~~~~
doio.c: In function 'Perl_PerlProc_pipe_cloexec':
doio.c:372:9: error: implicit declaration of function 'pipe2'; did you mean 'pipe'? [-Wimplicit-function-declaration]
372 | pipe2(pipefd, O_CLOEXEC),
| ^~~~~
doio.c:125:32: note: in definition of macro 'DO_GENOPEN_EXPERIMENTING_CLOEXEC'
125 | int res = (GENOPEN_CLOEXEC), eno;
| ^~~~~~~~~~~~~~~
doio.c:371:5: note: in expansion of macro 'DO_PIPEOPEN_EXPERIMENTING_CLOEXEC'
371 | DO_PIPEOPEN_EXPERIMENTING_CLOEXEC(PL_strategy_pipe, pipefd,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
doio.c: In function 'Perl_PerlSock_accept_cloexec':
doio.c:408:9: error: implicit declaration of function 'accept4'; did you mean 'accept'? [-Wimplicit-function-declaration]
408 | accept4(listenfd, addr, addrlen, SOCK_CLOEXEC),
| ^~~~~~~
doio.c:125:32: note: in definition of macro 'DO_GENOPEN_EXPERIMENTING_CLOEXEC'
125 | int res = (GENOPEN_CLOEXEC), eno;
| ^~~~~~~~~~~~~~~
doio.c:406:5: note: in expansion of macro 'DO_ONEOPEN_EXPERIMENTING_CLOEXEC'
406 | DO_ONEOPEN_EXPERIMENTING_CLOEXEC(
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
make[3]: *** [makefile:266: doio.o] Error 1

Start by reproducing the GCC 14 build failure, then inspect doio.c at the Perl_PerlLIO_dup2_cloexec, Perl_my_mkstemp_cloexec, Perl_PerlProc_pipe_cloexec, and PerlSock_accept_cloexec call sites, along with the Perl_my_mkostemp definition in util.h. Check the surrounding feature and platform checks before determining the compatibility change; done means the affected build completes without implicit-function-declaration errors.