lto gimple types and debug info

[Paolo Bonzini]

>>>> For that matter, "print sizeof(X)" should print the same value when 
>>>> debugging optimized code as when debugging unoptimized code, even if 
>>>> the compiler has optimized X away to an empty structure!
>>>
>>> I disagree.  sizeof(X) in the code will return a value as small as 
>>> possible in that case (so that malloc-ing an array of structures) 
>>> does not waste memory, and the debugger should do the same.
> 
> I don't think that's a viable option.  The value of sizeof(X) is a 
> compile-time constant, specified by a combination of ISO C and platform 
> ABI rules.  In C++, sizeof(X) can even be used as a (constant) template 
> parameter, way before we get to any optimization.

Then you are right.  This adds another constraint...

Paolo