[Bug c/85182] _Static_assert is less than useful in a static inline

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85182

--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
This is how static assertions are defined in C11, not a bug in GCC: it's a 
constraint violation if the constant expression compares equal to 0, 
regardless of the context in which the declaration appears (thus, a 
constraint violation in a function that is never called, for example).