gas dwarf2 support uses wrong address size

[Nick Clifton]

Hi Alex,

> Index: gas/ChangeLog
> from  Alexandre Oliva  <aoliva@redhat.com>
> 
> 	* dwarf2dbg.c (DWARF2_ADDR_SIZE): New macro.
> 	(dwarf2_finish): Use it.
> 	* doc/internals.texi (DWARF2_ADDR_SIZE): Document it.
> 	* config/tc-mips.h (DWARF2_ADDR_SIZE): Override.

Approved - please apply.

Cheers
        Nick