[Bug target/105523] Wrong warning array subscript [0] is outside array bounds

[lh_mouse at 126 dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105523

--- Comment #10 from LIU Hao <lh_mouse at 126 dot com> ---
(In reply to Andrew Pinski from comment #8)
> That inline-asm is not correct and GCC does not understand segments if you
> don't use named address space feature.
> 

Named address space is not supported unless a GNU standard is selected.

https://gcc.godbolt.org/z/nbEMz6xMq

```
int
read_gs_30(void)
  {
    return *(int* __seg_gs) 0x30;
  }
```

With `-std=c99`:
```
<source>: In function 'read_gs_30':
<source>:4:18: error: expected ')' before '__seg_gs'
    4 |     return *(int* __seg_gs) 0x30;
      |             ~    ^~~~~~~~~
      |                  )
Compiler returned: 1
```