[Bug target/80162] [5/6/7 Regression] ICE on invalid code (address of register variable)

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80162

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Ugh, but that patch breaks:
typedef int v8 __attribute__ ((vector_size (32)));
register v8 u asm ("xmm7");

int
foo (int i)
{
  return u[i];
}

int
bar (void)
{
  return u[5];
}

We could perhaps add an optional argument to
c_mark_addressable/cxx_mark_addressable that would be true when called to build
ARRAY_REF (in that case we wouldn't want to see through VCEs) and when actually
taking address (in that case we do want that).