[Bug tree-optimization/108306] false-positive -Warray-bounds warning emitted with -fsanitize=shift

[kees at outflux dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108306

--- Comment #7 from Kees Cook <kees at outflux dot net> ---
(In reply to Kees Cook from comment #6)
> Sorry, I forgot to include those details fully! Here's how I'm seeing it:
> 
> $ gcc --version
> gcc (GCC) 13.0.0 20230105 (experimental)
> ...
> $ gcc -O2 -fno-strict-overflow -fsanitize=shift -Warray-bounds -c -o
> /dev/null poc.c

In function 'psi_group_change',
    inlined from 'psi_task_switch' at poc.c:25:2:
poc.c:15:30: warning: array subscript 32 is above array bounds of 'unsigned
int[4]' [-Warray-bounds=]
   15 |                         tasks[t]++;
      |                         ~~~~~^~~
poc.c: In function 'psi_task_switch':
poc.c:6:14: note: while referencing 'tasks'
    6 | unsigned int tasks[NR_PSI_TASK_COUNTS];
      |              ^~~~~

(mispaste)