* run_make_tests.pl: set $port_type to be 'VMS-DCL' when the test are
run from the VMS DCL Interpreter. When the tests are run from GNV
on VMS, the $port_type will be 'UNIX'.
* run_make_tests.com: VMS search list support. This is needed for
using a search list such as prj_root = lcl_root:,vms_root:,src_root:
for building and testing.