My configuration:

./configure  --with-apache=../apache-1.3.9
--with-ftp --with-mysql=shared,/opt/mysql --enable-track-vars
--with-config-file-path=/etc --with-gd=shared,../gd-1.3 --with-freetype
--with-imap=/usr/src/imap/c-client --with-mm --with-pdflib=../pdflib-2.01
--enable-thread-safety --with-tiff-dir=/usr/lib --with-jpeg-dir=/usr/lib
--enable-trans-sid --enable-sysvshm --enable-sysvsem
--with-xml=shared,../apache-1.3.9/src/lib/expat-lite/

And here's the offending output of `make':

gcc -DHAVE_CONFIG_H -I. -I. -I../.. -I../../libzend -I../../TSRM -I/usr/src/www/
php4/../apache-1.3.9/src/include -I/usr/src/www/php4/../apache-1.3.9/src/os/unix
   -I/usr/src/imap/c-client/include   -I/usr/local/include -I../.. -I../../libze
nd    -g -O2 -g -O2 -c session.c
session.c: In function `php3_session_name':
session.c:559: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_module_name':
session.c:584: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_set_save_handler':
session.c:620: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_save_path':
session.c:652: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_id':
session.c:677: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_register':
session.c:702: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_unregister':
session.c:721: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_is_registered':
session.c:741: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_encode':
session.c:765: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_decode':
session.c:777: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_start':
session.c:793: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_destroy':
session.c:805: warning: initialization makes pointer from integer without a cast
session.c: In function `session_adapt_uris':
session.c:817: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_session_unset':
session.c:835: parse error before `*'
session.c:837: `ps_globals' undeclared (first use this function)
session.c:837: (Each undeclared identifier is reported only once
session.c:837: for each function it appears in.)
session.c: In function `php3_rinit_session':
session.c:884: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_rshutdown_session':
session.c:903: warning: initialization makes pointer from integer without a cast
session.c: In function `php3_minit_session':
session.c:919: warning: assignment makes pointer from integer without a cast
make[2]: *** [session.o] Error 1
make[2]: Leaving directory `/usr/src/www/php4/ext/session'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/src/www/php4/ext'