PATCH:[darwin] fix load of a misaligned double word

[David Edelsohn]

>>>>> Hartmut Penner writes:

> PR target/13674
> * gcc/config/rs6000/rs6000.md (*movdf_hardfloat64):
> Disregard memory - general register alternative.

-  [(set (match_operand:DF 0 "nonimmediate_operand" "=Y,??r,!r,f,f,m,!cl,!r,!r,!r,!r")
+  [(set (match_operand:DF 0 "nonimmediate_operand" "=?Y,?r,!r,f,f,m,!cl,!r,!r,!r,!r")

	Why are you decreasing the number of "?" on the "ld" case while
you disparage memory on the "std" case? 

Thanks, David