Disable .gnu.hash on MIPS targets

[Eric Christopher]

Richard Sandiford wrote:
> Unfortunately, the new .gnu.hash stuff seems to be fundamentally
> incompatible with the MIPS ABI.  .gnu.hash wants .dynsym to be sorted
> in such a way that symbols with the same hash value are grouped together,
> whereas with the MIPS ABI, symbols that don't have GOT entries must come
> before symbols that do.  The .dynsym entries for the latter group must
> also have the same order as the corresponding GOT entries.
> 
> So, this patch makes ld error out if you try to create .gnu.hash
> on MIPS.  This is necessary to get a working library with glibc HEAD.
> 
> Tested on mips64-linux-gnu, mips64-elf and mips-sgi-irix6.5.
> OK to install?
> 

OK. Thanks as always.

-eric