case-insensitive comparison of $*OS
case-insensitive comparison of $*OS

the test assumes the p5 insanity of "linux" vs. "MSWin32", but the specs
are silent on the exact case of the return value. (And on the exact return
value itself, for that matter).

b2gills/roast,dankogai/roast,cygx/roast,bitrauser/roast,skids/roast,laben/roast,b2gills/roast,zostay/roast,cygx/roast,niner/roast,cygx/roast,b2gills/roast,zostay/roast,laben/roast,skids/roast,dogbert17/roast,laben/roast,perl6/roast,dogbert17/roast,dankogai/roast,dankogai/roast,skids/roast,niner/roast,bitrauser/roast,niner/roast,zostay/roast