[Bug rtl-optimization/63804] [5 Regression] ice in find_oldest_value_reg with -g -O2

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63804

--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
trippels@gcc2-power8 status % cat freelist_test.ii
template <typename _Tp> struct A
{ 
  _Tp _M_i;
  void
  load ()
  { 
    _Tp a;
    __atomic_load (&_M_i, &a, 0);
  }
};
class B
{ 
  int *ptr;
  int tag;
};
class C
{
public:
  template <typename Allocator> C (Allocator, int);
  template <bool, int>
  void
  construct ()
  { 
    pool_.load ();
  }
  A<B> pool_;
};
class D
{ 
  int *px;
  int pn;
};
class F
{
public:
  F (int);
};
class G
{
public:
  G (int) : p_predicate_value (0) {}
  class readonly_property61 : F
  {
  public:
    readonly_property61 (int) : F (0) {}
  } p_predicate_value;
  D m_message;
};
void report_assertion (G);
template <typename, int threadsafe, int bounded>
void
run_test ()
{ 
  C b (0, 0);
  b.construct<threadsafe, bounded> ();
  report_assertion (0);
}
template <bool bounded>
void
run_tests ()
{ 
  run_test<C, 0, bounded> ();
}
void
freelist_teststest_method ()
{ 
  run_tests<false> ();
}