[RFC] generate maybe dependencies from the template

[Paolo Bonzini]

>>+# to maintain later.  In this particular case, you just have to be careful
>>+# to nest @if/@endif pairs correctly, because if you make a nesting error
>>+# configure will not warn you at all."
>  
> This is a bit misleading.  AFAICT, you can't have any nesting
> whatsoever.  It even works if the `if' condition happens to be
> satisfied, but if it doesn't, sed won't do the right thing:

You're right.  Well, I don't see any benefit in nesting (at least as far 
as the toplevel Makefile is concerned), but if people disagree I can 
modify the patch to follow your suggestion.

Paolo