[patch, libfortran] PR 32858 - printf()-capabilities for runtime_error

[FX Coudert]

Hi Thomas,

I daresay I'm a bit more anxious than Jerry about the portability of  
the system you're introducing, and the functions you're using. Are we  
garanteed that sprintf is available on all platforms? What about the  
use of __builtint_vsprintf, how is it resolved when no vsprintf()  
function is actually present in libc? I don't have time to look fully  
into that patch right now, but if you could just make sure about this  
before committing, I'd appreciate it. I'll try to do a bootstrap on  
mingw32, in any case, to see if that succeeds; I won't be able to  
report results from this bootstrap before monday evening at least.

Sorry for being picky and not so helpful...
FX