[rfa/threads] Convert thread event descriptors to code addrs

[Andrew Cagney]

>> (remote_check_symbols?)  Wouldn't that be equivalent to my original 
>> patch (wrong side of libthread_db)?  I suspect you want to add something 
>> to gdbserver (or just wait for Roland's updated libthread_db).
> 
> 
> Any remote client asking for a function address is going to want to put
> a breakpoint there, I would have guessed.  Thus we should return the
> breakpointable address.

Suggest re-reading roland's comments.  The contract is to convert a 
symbol "foo" to its value.  Not convert a symbol foo to a code address 
by doing a descriptor re-direction.

> Hum, maybe there is some use in having the descriptor... let me think
> about it.  This should go into the remote protocol doco one way or the
> other.

I think the protocol is pretty clear here.

Andrew