[Bug c++/91391] Bogus -Wcomma-subscript

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91391

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
...except when it's:

void
fn (int *a, int b, int c)
{
  a[b < c, b > c]; // should warn
}