[gfortran] Patch Ping**2

[Tobias Schlüter]

Tobias Schlüter wrote:
> This turned out to be a gimplifier bug, now PR22035.  Something as simple as
>    COMPLEX z, w
>    z = (1.,2.)
>    if (z/=w) call abort
>    end
> ICEs on the mainline currently.

... if optimization is enabled, in case you want to try this yourself.

- Tobi