It can't have a Makefile.PL faked-up from make_ext.pl, beacuse it needs to
define NO_PPPORT_H.
ext/Cwd/Changes Cwd extension Changelog
ext/Cwd/Cwd.pm Various cwd routines (getcwd, fastcwd, chdir)
ext/Cwd/Cwd.xs Cwd extension external subroutines
+ext/Cwd/Makefile.PL Cwd extension makefile maker
ext/Cwd/t/cwd.t See if Cwd works
ext/Cwd/t/taint.t See if Cwd works with taint
ext/Cwd/t/win32.t See if Cwd works on Win32