Running Redhat Linux 6.1 with the original version of gcc on here.  Trying to compile php3 version 3.0.17-dev with apache version 1.3.12...  Here's the message I get when the compile fails:

gcc -g -O2 -O2   -I. -I.   -I../apache_1.3.12/src/include -I../apache_1.3.12/src/os/unix                  -I/usr/local/include -I/usr/local/mysql/include/mysql    -c functions/microtime.c -o functions/microtime.o
functions/microtime.c: In function `php3_getrusage':
functions/microtime.c:152: storage size of `usg' isn't known
functions/microtime.c:155: `RUSAGE_SELF' undeclared (first use in this function)
functions/microtime.c:155: (Each undeclared identifier is reported only once
functions/microtime.c:155: for each function it appears in.)
functions/microtime.c:161: `RUSAGE_CHILDREN' undeclared (first use in this function)
make: *** [functions/microtime.o] Error 1

Here is what I am running for my configure statement:
./configure --with-mysql=/usr/local/mysql --with-apache=../apache_1.3.12 --enable-track-vars

Hope this helps figure out whats up with the compile.