[Bug target/77728] [5/6/7/8 Regression] Miscompilation multiple vector iteration on ARM

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728

--- Comment #19 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Indeed, with the above plus:
#include <stdarg.h>

int
fn1 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int
k, int l, int m, B<0> n, ...)
{
  va_list ap;
  va_start (ap, n);
  int x = va_arg (ap, int);
  va_end (ap);
  return x;
}

int
fn2 (int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int
k, int l, int m,
B<1> n, ...)
{
  va_list ap;
  va_start (ap, n);
  int x = va_arg (ap, int);
  va_end (ap);
  return x;
}

there is ABI change for fn1 but not fn2.  But we already get a warning with
your patch on that:
warning: Parameter passing changed for argument in function_arg_boundary
so perhaps no need to emit it for the second time.