Manifest constants (was const again)

[Walter Bright]

Bill Baxter wrote:
> Just like in D we have float[] x  as the improved syntax and float x[] 
> as legacy syntax, we could have both  "alias Y=X" as new-and-improved 
> and "alias X Y" as an aid to porting.  As for being confusing, doing it 
> the wrong way is going to be a compiler error, so I don't think it's a 
> big deal.

Looking it in the light of trying to avoid:
	enum int Y = X;
I think it is a big deal. The enum form wouldn't have any obvious 
problems like that.