[patch, fortran] Fix PR 69544

[Thomas Koenig]

Hi Dominique,

>  The patch fixes the ICE due to the missing gfc_current_locus in the
> last one, but the same should be applied to match_simple_where,
> otherwise one gets an ICE for statements such as
>
> if (n==10) where (txt(1:3) /= ''   )  y(1:3,i,j) = txt(1:3)

I can confirm that the bug exists.  Because the obvious and simple fix
caused a boatload of regressions for reasons I cannot yet understand, I
have opened PR 78178 for the other test case, and committed the existing
fix to trunk so far.

Am rebuilding my tree at the moment, maybe this will help.

Regards

	Thomas