Upated to match change to run_make_tests and some future fixes to
make on VMS.
* arscan.c: Use ANSI compatible pragmas instead of VAX C extensions.
* tests/scripts/features/archives: Fix tests to use VMS rules and
answers when running on VMS and using DCL as a shell.
* tests/scripts/features/vpath3: Fix epected answer on test when
run on VMS.
* tests/scripts/vms/library: (New) Test the VMS library rules that
are not tested by existing tests.