sh atomics config

[Joern RENNECKE]

Benjamin Kosnik wrote:

>>The host CPU is irrelevant.  The preferred implementation is dependent 
>>on the
>>target CPU and operating system.
>>Moreover, this has to work with multilibs.
>>    
>>
>
>What are the possible target_cpu values where __SH4A__ is defined?
>  
>
The sh configurations support a configuration option --with-multilib-list to
specify the cpu dimension of the multilib list.  Hence, it could appear with
any sh configuation - although sh5 / sh64 ones would not be exepcted to 
work.