foreach (x; a .. b) and foreach_reverse (x; a .. b) should be disallowed for floats

[Andrei Alexandrescu]

Consider:

     foreach (x; 1.0 .. 4.1) writeln(x);
     foreach_reverse (x; 1.0 .. 4.1) writeln(x);

This sucks. foreach with interval for floating-point types should be 
disallowed.


Andrei