[PATCH] MIPS r6 support

[Torbjörn Granlund]

Thanks for this proposed GMP change.  We indeed would like to port GMP
to mips r6; what has held us back for many years is lack of a suitable
test platform.

I don't much like the approach you've taken.

(1) We don't use cpp for our assembly, we use m4.  Your change to
m4-ccas affects all targets, which is not good.

(2) We should use separate asm files in a separate subdirectory
(mips32/r6 and mips64/r6).  Conditionals all over asm code is not good.

(3) Presumably, modern r6 implementations benefit from latency
scheduling, which is something the new ISA facilitates.

(4) We need changes to configure.ac, and config.* before r6 really
works.

-- 
Torbjörn
Please encrypt, key id 0xC8601622