[Bug c/97986] [12/13/14/15 Regression] ICE in force_constant_size when applying va_arg to VLA type since r6-91-gf8e89441bc5518f4

[jsm28 at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97986

--- Comment #10 from Joseph S. Myers <jsm28 at gcc dot gnu.org> ---
I think my previous comment still applies: when an array type is passed to
va_arg, evaluate side effects of the arguments, warn and (except for non-VLAs
in C90 mode) generate a call to __builtin_trap that's evaluated after the side
effects from the arguments. The resulting expression should still have the
array type (it could be passed to sizeof, for example).