[Bug middle-end/105762] New: [12 Regression] -Warray-bounds false positives for integer-to-pointer casts

[roland at gnu dot org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105762

            Bug ID: 105762
           Summary: [12 Regression] -Warray-bounds false positives for
                    integer-to-pointer casts
           Product: gcc
           Version: 12.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: roland at gnu dot org
  Target Milestone: ---

This code:

```
void crash(void) {                                                              
  volatile int* ptr = (volatile int*)1ul;                                       
 *ptr = 1;                                                                      
}
```

now gets:

```
warning: array subscript 0 is outside array bounds of 'volatile int[0]'
[-Warray-bounds]
```

This is a regression since GCC 11.

Reproduced on aarch64-elf and x86_64-elf targets as of 12 branch commit
2c11a9a380e7af333e19d6e576a889646d699b2a