[Bug tree-optimization/79908] ICE in gimplify_expr (gimplify.c:12155) gimplification failed

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79908

--- Comment #4 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Any fix for this must also handle this reduced test case:

typedef __builtin_va_list __gnuc_va_list;
typedef __gnuc_va_list va_list;

void
foo (va_list args)
{
  va_list ap;
  __builtin_va_copy (ap, args);
  (void)__builtin_va_arg (ap, int);
  __builtin_va_end(ap);
}