PATCH: Factor __aeabi_atexit into its own object file

[Paolo Carlini]

Mark Mitchell wrote:

>__attribute__((nothrow)) is the C equivalent of "throw ()".  In C++
>programs, you should just use "throw()", but in C programs, you can use
>"__attribute__((nothrow))".  Of course, in C, this only matters if
>you're using -fexceptions so that you can unwind through C code.
>  
>
I see, in fact the specific thing I'm not familiar with is unwinding 
through C code...

[snip]

Thanks a lot about the many additional details and explanations!

Thanks,
Paolo.