[patch] change to MIPS 4650 instruction support

[Daniel Jacobowitz]

The 4650 support in binutils changed after 2.8.1 - it now both adds the
new instructions (mad, madu, mul) and imposes restrictions on the
available instructions (double floating point).  Up till now, GCC has
translated -mmad on its command line into -m4650 in binutils, but that
doesn't work any more.

This is my proposed solution - I add a separate flag, implied by
-m4650, to control the new instructions.

Comments?  The patch is actually against 2.10.91.0.2 rather than HEAD,
but I can provide it for the head if wanted.

-- 
Daniel Jacobowitz                           Debian GNU/Linux Developer
Monta Vista Software                              Debian Security Team
                         "I am croutons!"