You can generally see the configure options a perl was built with by looking at perl -V:config_args, unless Configure was run manually (i.e. without the -d flag) and some answers were changed, or a Policy.sh was used to set some options, or the config.sh file was manually changed after running Configure.

By default, the vendor stuff isn't set; I think you need to recompile perl to get it set; see "Directories for vendor-supplied add-on files" in INSTALL.