Summary and Info:
After the X server upgrade SWT was broken, but compiling from source did not work and it tried to uninstall Sun's jdk and jre. I changed the server, and the depends and everything worked.

Steps to Reproduce:
This PKGBUILD worked for me:
# $Id: PKGBUILD,v 1.12 2007/08/26 10:42:18 jgc Exp $
# Maintainer: simo <simo@archlinux.org>
pkgname=swt
pkgver=3.3
pkgrel=1
pkgdesc="An open source widget toolkit for Java"
_date=200706251500
arch=(i686 x86_64)
url="http://www.eclipse.org/swt/"
license=('EPL')
depends=('java-runtime')
makedepends=('apache-ant' 'jre' 'jdk' 'libxtst' 'mesa' 'libgnomeui' 'xulrunner')
source=(http://mirror.calvin.edu/eclipse/downloads/drops/R-${pkgver}-${_date}/swt-${pkgver}-gtk-linux-x86.zip
build-swt.xml)
noextract=(swt-${pkgver}-gtk-linux-x86.zip)
md5sums=('7398cdf9340cb131b76ed98495239520'
'f5e548bc26a0f1f3c18131be76face40')
if [ "${CARCH}" = "x86_64" ]; then
source=(http://download.eclipse.org/eclipse/downloads/drops/R-${pkgver}-${_date}/swt-${pkgver}-gtk-linux-x86_64.zip
build-swt.xml)
noextract=(swt-${pkgver}-gtk-linux-x86_64.zip)
fi

build() {
cd ${startdir}/src
unzip -jqo ${startdir}/src/swt-${pkgver}-gtk-linux-*.zip "*src.zip"
unzip -qo src.zip
rm -rf about_files
mkdir src
mv org src/
cp build-swt.xml build.xml || return 1

[ "${CARCH}" = "x86_64" ] && export SWT_PTR_CFLAGS=-DSWT_PTR_SIZE_64

make -f make_linux.mak make_awt || return 1
make -f make_linux.mak make_swt || return 1
make -f make_linux.mak make_atk || return 1
make -f make_linux.mak make_gnome || return 1
MOZILLA_INCLUDES="`pkg-config --cflags xulrunner-xpcom`" \
MOZILLA_LIBS="`pkg-config --libs xulrunner-xpcom` -Wl,-R/opt/mozilla/lib/xulrunner" \
make -f make_linux.mak make_mozilla || return 1
XULRUNNER_INCLUDES="`pkg-config --cflags xulrunner-xpcom`" \
XULRUNNER_LIBS="`pkg-config --libs xulrunner-xpcom` -Wl,-R/opt/mozilla/lib/xulrunner" \
make -f make_linux.mak make_xulrunner || return 1

make -f make_linux.mak make_cairo || return 1
make -f make_linux.mak make_glx || return 1

ant compile || return 1
cp version.txt build/version.txt
cp src/org/eclipse/swt/internal/SWTMessages.properties build/org/eclipse/swt/internal/

ant jar || return 1

install -D -m644 swt.jar ${startdir}/pkg/usr/share/java/swt.jar
mkdir -p ${startdir}/pkg/usr/lib
install -m755 *.so ${startdir}/pkg/usr/lib/
}