[Ur] sanity checking

[Adam Chlipala]

Karn Kallio wrote:
> Well, looking at the code I thought that it should output both, 
> because gcc
> is supposed to support non-constant initializers.  But I am not really any
> help, because I do not know enough about gcc to say.  One thing that I do
> notice in your example is that the printf should be leaving an integer in the
> __uwf_1 position of tmp but how could there be space for it (as uw_unit should
> occupy 0 size) ...
>    

I think this is a confusion between the comma separator between 
initializer elements and the comma operator in expressions.  I think my 
use of parentheses triggers interpretation as the latter, not the former.

I'm going to try to figure out the GCC bug report procedure and submit 
this test case.