[patch] mkcshadow improvements

[Benjamin Kosnik]

> Since "we" are the implementor, "we" can choose to define any
> instance of undefined behavior.  And, in fact, gcc-2.96 seems to 
> permit it.  But it's academic, because it doesn't seem safe enough 
> to be useful.

Whoa! So strident sounding are you! 

I suppose this same property allows us to call this thing _C_ (reserved 
for implementors) instead of _C_something_that_makes_sense_to_nathan?

;)

-benjamin