How to avoid code duplication in my new RTEMS port

[Chris Johns]

Joel Sherrill wrote:
> I had considered starting to move libcpu parts to libbsp/shared or specific
> BSPs but we couldn't really do this before git. And now, with the Waf
> discussions, it seems wise to hold off.

The various bits and pieces mix with conditional logic and took me a 
while to decode the relationships back to the specific BSPS. Stability 
by not moving would be helpful. Headers are particularly sensitive.

Chris