[Bug rtl-optimization/102733] missing fs:0 store when followed by one to gs:0

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102733

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 55238
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55238&action=edit
Patch which I will be testing

This adds a check for the address space in DSE.

Even tested:
```
void test_null_store_fs_gs (void)
{
  int __seg_fs *fs = (int __seg_fs *)0;
  *fs = 1; 

  int __seg_gs *gs = (int __seg_gs *)0;
  *gs = 2;  
  *fs = 3; 
}
```

And only 2/3 are emitted (in that order) which is the correct DSE even.