[Bug c/108128] missing -Wshift-overflow warning

[vincent-gcc at vinc17 dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108128

--- Comment #1 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
Well, with -pedantic, GCC also warns on "enum { A = 1 << 31 };".