[gfortran] Updates to ISHFT translation

[Tobias Schlüter]

Tobias Schlüter wrote:
> (signed_type, a), ...))").  This patch fixes this, and reformats a few lines
> in the function.

This description was inaccurate.

>    num_bits = convert (TREE_TYPE (arg2),
>  		      build_int_cst (NULL, TYPE_PRECISION (type)));
> -  cond = fold (build2 (GE_EXPR, boolean_type_node, width,
> -		       convert (TREE_TYPE (arg2), num_bits)));
> +  cond = fold (build2 (GE_EXPR, boolean_type_node, width, num_bits));

I removed a superfluous conversion here, consider the ChangeLog updated
accordingly.

- Tobi