zconf.h header file is missing for 32 bits arch

zconf.h was moved to multiarch directory (zlib1g-dev package) because it contains an arch dependant declaration.
Problem is programs using zlib doesn't compile anymore using 32bits target arch. (zconf.h is not found)

I suppose a 32 bits version of zconf.h should be added into lib32z1-dev package ?

Description: Ubuntu Raring Ringtail (development branch)
Release: 13.04
x86_64
lib32z1-dev 1:1.2.7.dfsg-13ubuntu2

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: lib32z1-dev 1:1.2.7.dfsg-13ubuntu2
ProcVersionSignature: Ubuntu 3.8.0-12.21-generic 3.8.2
Uname: Linux 3.8.0-12-generic x86_64
ApportVersion: 2.9.1-0ubuntu1
Architecture: amd64
Date: Thu Mar 14 20:54:10 2013
InstallationDate: Installed on 2013-02-21 (21 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130221)
MarkForUpload: True
ProcEnviron:
 SHELL=/bin/bash
 TERM=xterm
 PATH=(custom, no user)
 LANG=fr_FR.UTF-8
 XDG_RUNTIME_DIR=<set>
SourcePackage: zlib
UpgradeStatus: No upgrade log present (probably fresh install)