t/noenv.t: fix error on Win32
t/noenv.t: fix error on Win32

Use File::Spec::splitpath to portably get the directory portion of a path and
use File::Spec::canonpath to portably compare file paths.

packy/ack2,gregory-nisbet/ack2,packy/ack2,gregory-nisbet/ack2,karenetheridge/App-Ack,petdance/ack2,karenetheridge/App-Ack,h3xx/ack2,shlomif/ack2,petdance/ack2,openstrike/ack2,packy/ack2,gregory-nisbet/ack2,packy/ack2,petdance/ack2,openstrike/ack2,gregory-nisbet/ack2,packy/ack2,karenetheridge/App-Ack,petdance/ack2,h3xx/ack2,openstrike/ack2,h3xx/ack2,petdance/ack2,karenetheridge/App-Ack,packy/ack2,h3xx/ack2,h3xx/ack2,petdance/ack2,openstrike/ack2,shlomif/ack2,shlomif/ack2,petdance/ack2,packy/ack2,petdance/ack2,gregory-nisbet/ack2,shlomif/ack2,h3xx/ack2,h3xx/ack2,openstrike/ack2,karenetheridge/App-Ack,openstrike/ack2,karenetheridge/App-Ack,gregory-nisbet/ack2,openstrike/ack2,packy/ack2,karenetheridge/App-Ack,gregory-nisbet/ack2,shlomif/ack2,h3xx/ack2,gregory-nisbet/ack2,karenetheridge/App-Ack,openstrike/ack2,shlomif/ack2