RFC: PATCH to layout_decl for middle-end/27945

[Jason Merrill]

Jason Merrill wrote:
> So something like your patch is necessary.

I think a simpler change would be to just select between

         DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), BITS_PER_UNIT);

and

         if (known_align)
           DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), known_align);

for packing, based on a langhook.

Jason