[Bug c/68193] _Generic -Woverflow false alarm

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193

--- Comment #4 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
I agree delaying warnings would help, but you'd need to distinguish 
warnings relating to execution of the code that should be disabled in 
unevaluated code from warnings that should always be present (which 
include but aren't limited to pedwarns).  For example, you shouldn't lose 
a diagnostic for an implicit function declaration just because it's in an 
unevaluated _Generic selection.