https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101446
--- Comment #8 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- I think this is a bug. Negative-size arrays are an unconditional error. Zero-size arrays should be a pedwarn-if-pedantic, regardless of whether the 0 is explicit or deduced from an initializer.
