[Bug tree-optimization/92689] Improve stmt_may_clobber_ref_p_1 on constant memory reference

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92689

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The argument p could have been a non const when it was passed to foo.

That is outside of the this TU:
static int t;
void gggg(void)
{
  foo (&t);
}

void fn(void)
{
  t++;
}