packager: 32-bit javafxpackager creates invalid package based on 64-bit JDK

When packager in 32-bit JDK tries to build package based on 64-bit JDK (<fx:platform basedir="..."/>) the generated executable fails with this message:

libjvm.so is not found in the bundled runtime.
Failed to launch JVM

To reproduce:
1) download and unpack HelloWorld.tar.bz2
2) run update_props.sh $BASE_JAVA_HOME # - 32-bit java at this $BASE_JAVA_HOME
3) edit simple-project.properties and edit ext.jdk to point at $EXTERNAL_JAVA_HOME, which is your 64-bit JDK
4) run "ant -f simple-build.xml deploy-all-diff-jre"
5) run "./dist/bundles/HelloWorld/HelloWorld"
6) get the wrong output