[PATCH] Fix PR30147, fold_read_from_constant_string ICEing on aggregate return type

[Paolo Bonzini]

Richard Guenther wrote:
> This fixes PR30147 where we try to fold
> 
>   *(charD.21[1:1] *) "K"
> 
> to 'K' of type (charD.21[1:1] *).  On fold-converting to that type we
> ICE.
> 
> Fixed by only folding a read if the return type is integer.

Why not INTEGRAL_TYPE_P?

Paolo