[Bug tree-optimization/122153] New: cselim and cselim-lited should be able to handle `= {}`

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122153

            Bug ID: 122153
           Summary: cselim and cselim-lited should be able to handle `=
                    {}`
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: pinskia at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
struct s1
{
  int t;
};
void g(struct s1*);
struct s1 f(int *a, int c, int d)
{
  struct s1 r;
  int t1;
  if (c < d)
  {
    r = (struct s1){};
    t1 = c;
  }
  else
  {
    r = (struct s1){};
    t1 = d;
  }
  g(&r);
  r.t = t1;
  return r;
}

```

Right now this is only handled by sink but really the min should be able to
optimize at phiopt1.