[Bug c/108896] provide "element_count" attribute to give more context to __builtin_dynamic_object_size() and -fsanitize=bounds

[kees at outflux dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896

--- Comment #42 from Kees Cook <kees at outflux dot net> ---
Exciting! Are you able to attach the latest patch? I'd love to try it out. I've
been testing Clang's version as well:
https://reviews.llvm.org/D148381