[h8300] increase dwarf address size

[Jeff Law]

On 05/09/2012 06:27 PM, DJ Delorie wrote:
> H8/300 cpus have a larger-than-64k address space, despite 16-bit
> pointers.  OK to apply?  Ok for 4.7 branch?
>
> See also http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48231
>
> 	* config/h8300/h8300.h (DWARF2_ADDR_SIZE): Define as 4 bytes.
My recollection was that the H8/300 only had a 64k address space and 
that the larger address spaces showed up in later processors (H8/300H).

Regardless, shouldn't DWARF2_ADDR_SIZE be POINTER_SIZE / BITS_PER_UNIT? 
  That'll give the larger DWARF2_ADDR_SIZE on the modern widgets, but 
still do the right thing for the ancient H8/300.

My other relevant recollection was that we don't support C++ on the 
H8/300 series.

jeff