I'm sorry if this report doesn't contain enough information - I'm not a C programmer.  But I'll try to describe the problem as best I can.  

My configure command:
./configure --with-mysql=/usr/local/
mysql --with-apache=../apache_1.3.9 --with-config-file-path=/http/bcbsnc/php

The compilation (using either AIX cc or gcc) both halt at the same place.  AIX' cc' error message seems more useful:

        /bin/sh ../../libtool --silent --mode=compile cc -DHAVE_CONFIG_H -I. -I.
 -I../.. -I../../libzend -I../.. -I../../libzend -I/http/bcbsnc/src/apache_1.3.9
/src/include -I/http/bcbsnc/src/apache_1.3.9/src/os/unix  -I/usr/local/mysql/inc
lude      -g -g -c -o apache.lo apache.c

"/http/bcbsnc/src/apache_1.3.9/src/os/unix/os.h", line 119.12: 1506-343 (S) Redeclaration of dlerror differs from previous declaration on line 35 of "/usr/include/dlfcn.h".

"/http/bcbsnc/src/apache_1.3.9/src/os/unix/os.h", line 119.12: 1506-050 (I) Return type "const unsigned char*" in redeclaration is not compatible with the previous return type "unsigned char*".

Though I'm not a C programmer, it looks like there is a conflicting declaration of dlfcn.h .  I was able to fix this problem and complete the compilation by going to my "apache_1.3.9" directory and modifying line 119 of /s
rc/os/unix/os.h to be "char *dlerror(void);" instead of "const char *dlerror(void);"

I wonder, does this have anything to do with the fact that php.h has definitions like this:

#if HAVE_DLFCN_H && !((defined(_AIX) || defined(AIX)) && APACHE)
#  include <dlfcn.h>
#endif
# endif
#endif

but files like libzend/zend_config.h have less-restrictive definitions like this?

#ifdef HAVE_DLFCN_H
# include <dlfcn.h>
#endif

Anyway, I apologize if this is not enough information, but I hope this report will help.