In 2.0.45, --enable-layout no longer works. The argument you give gets incorrectly looked up in the ./srclib/apr/config.layout file rather than just the ./config.layout file, and configure fails. Same problem would likely occur with ./srclib/apr-util/config.layout as well, if it were able to get that far.
A fix for this has been committed to 2.1-dev and will be suggested for merging into 2.0.46-dev. Here is the fix: http://cvs.apache.org/viewcvs.cgi/httpd-2.0/configure.in.diff?r1=1.246&r2=1.247 Thanks for your report, and I'm sorry that this was broken in 2.0.45. The regression was discovered at the last minute, and due to the high severity of some of the issues resolved by 2.0.45 it was felt that it was best to get 2.0.45 out the door.
this has now been merged into 2.0.46-dev.