Reverted previous change to what was believed to be an errant test case.

Also added a test for NaN safety

test/test_operations.coffee

@@ -175,4 +175,7 @@ ok a is '123456'
 ok + +1 is - -1
 
 #891: incorrect inversion of chained comparisons
-ok (true unless 0 > 1 > 2)
+(->
+  ok (true unless 0 > 1 > 2)
+  ok (true unless (NaN = 0/0) < 0/0 < NaN)
+)()

test/test_switch.coffee

@@ -59,7 +59,7 @@ result = switch
   when '' not of {''}           then 2
   when [] not instanceof Array  then 3
   when true is false            then 4
-  when 'x' > 'y' > 'z'          then 5
+  when 'x' < 'y' > 'z'          then 5
   when 'a' in ['b', 'c']        then 6
   when 'd' in (['e', 'f'])      then 7
   else ok