[Bug tree-optimization/109561] [13/14/15/16 regression] -Wmaybe-uninitialized false positive with std::optional

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109561

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |15.1.0
           Keywords|                            |needs-bisection

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This looks like it was fixed in GCC 15 but there is still some missing
optimizations.

in .optimized:
```
  D.57945 = {};
  SR.83_44->i = {};
  _34 = (void *) ivtmp.116_94;
  _17 = MEM[(bool *)_34 + 16B];
  pretmp_41 = MEM[(struct _Optional_payload_base &)&D.57945 + 8]._M_engaged;
```

In .fre3:
```
  D.57945 = {};
  SR.83_7->i = {};
  _10 = &MEM[(struct _Optional_payload *)SR.83_7 + 8B].D.55976;
  _17 = MEM[(struct _Optional_payload_base *)SR.83_7 + 8B]._M_engaged;
  if (_17 != 0)
    goto <bb 4>; [50.00%]
  else
    goto <bb 16>; [50.00%]

  <bb 4> [local count: 477815112]:
  _18 = MEM[(struct _Optional_payload_base &)&D.57945 + 8]._M_engaged;
```

At this point _18/pretmp_41 should be 0.