[Bug middle-end/97943] [11 Regression] ICE with __builtin_clear_padding on flexible array member

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97943

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
I think we should reject trying to clear the padding of a flexible/zero-length
array, with error rather than sorry.  And handle an array at the end of a
struct like any other array.  Nobody should be using this builtin with the
struct hack, it's impossible for it to do anything sensible.